Television receiver that detects electric field information from a received television signal and stabilizes a detected synchronizing signal according to the electric field information

ABSTRACT

A television signal receiver has: receiving means for receiving a television signal; detecting means for detecting a pulse of a video signal obtained from the receiving means; phase detecting means for detecting the phase of the pulse; video signal stabilizing means for conducting image-stabilization on the video signal obtained in the receiving means, in accordance with control information obtained from the phase detecting means and based on the reception disturbance state; and displaying means for displaying a video signal obtained from the video signal stabilizing means. According to this configuration, therefore, the video signal can be stabilized by the video signal stabilizing means, so that disturbance of an image can be reduced.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a television receiver, an antenna diversitycontroller, a synchronizing signal stabilizer, a luminance signalstabilizer, a color signal stabilizer, a video signal stabilizer, and amethod of transmitting a television signal and a television signalreceiver.

2. Related Art of the Invention

Recently, a car television set which is one of video signal receiversfor a mobile unit comes into widespread use.

Hereinafter, an example of such a car television set of the prior artwill be described with reference to the drawings. FIG. 40 is a viewshowing the configuration of a car television set of the prior art.

In the figure, 901 designates diversity antennas, 902 designates a tunerunit, 903 designates a video signal processing unit, 904 designates adisplay control unit, 905 designates a display unit, 906 designates anaudio signal processing unit, and 907 designates an audio output unit.

The operation of the thus configured car television set will bedescribed.

First, a television signal obtained by the diversity antennas 901 issubjected to video detection and audio detection in the tuner unit 902to be divided into a video signal and an audio signal. The audio signalis subjected to a filtering process by the audio signal processing unit906, and then transmitted to the audio output unit 907, therebyobtaining an audio output.

On the other hand, the video signal obtained from the tuner unit 902 issubjected to a color signal process and a synchronizing signal processin the video signal processing unit 903 to be divided into RGB signals,and then transmitted to the display control unit 904. The displaycontrol unit transmits the RGB signals and the synchronizing signalobtained from the video signal processing unit 903 to the display unit905, and an image is output from the display unit 905.

In the configuration, however, multipaths of the RF video signal andvariation of the electric field strength during mobile reception causethe video and audio signals to be disturbed. This produces problems asfollows. In the video signal, a disturbance appears in the synchronizingsignal, so that the image flows or is distorted. In the audio signal,many pulsative noises are produced.

On the other hand, in the above configuration, however, wave multipathsin mobile reception cause the video and audio signals to be disturbed.This produces a problem in that disturbances such as image flow,distortion, image skip, and multiple images occur in the video signal.At present, the ghost cancel system using a ghost cancel referencesignal (GCR) is employed. However, the system requires several secondsuntil an effect is attained, and has a problem in that the system cannotattain an effect in mobile reception.

SUMMARY OF THE INVENTION

In view of the problems of the related art, it is an object of theinvention to provide a television receiver, an antenna diversitycontroller, a synchronizing signal stabilizer, a luminance signalstabilizer, a color signal stabilizer, and a video signal stabilizerwhich can stabilize an image in mobile reception and reduce noises in anaudio signal as compared with the prior art.

In view of the problems of the related prior it is an object of theinvention to provide a method of transmitting a television signal and atelevision signal receiver in which an image in mobile reception can bestabilized as compared with the prior art.

A television receiver of the invention comprises:

receiving means for receiving a television signal;

synchronizing signal detecting means for detecting a synchronizingsignal of a video signal obtained from said receiving means;

electric field information detecting means for detecting electric fieldinformation from a signal obtained from said receiving means;

synchronizing signal stabilizing means for stabilizing the detectedsynchronizing signal on the basis of the electric field information;

display controlling means for controlling a display of the video signalby using the stabilized synchronizing signal; and

displaying means for displaying a signal output from said displaycontrolling means.

A television receiver of the invention comprises:

receiving means for receiving a television signal;

synchronizing signal detecting means for detecting a synchronizingsignal of a video signal obtained from said receiving means;

synchronizing signal stabilizing means for stabilizing the detectedsynchronizing signal;

video signal stabilizing means for stabilizing the video signal obtainedfrom said receiving means, by using the stabilized synchronizing signal,and for outputting the stabilized video signal;

display controlling means for controlling a display of the stabilizedvideo signal by using the stabilized synchronizing signal; and

displaying means for displaying a signal output from said displaycontrolling means.

A television receiver of the invention comprises:

receiving means for receiving a television signal;

synchronizing signal detecting means for detecting a synchronizingsignal of a video signal obtained from said receiving means;

synchronizing signal stabilizing means for stabilizing the detectedsynchronizing signal;

display controlling means for controlling a display of the video signalby using the stabilized synchronizing signal; and

liquid crystal displaying means for conducting a liquid crystal displayof a signal output from said display controlling means.

An antenna diversity controller of the invention comprises: antennas ofa diversity system for receiving a television wave; receiving means ofthe diversity system for receiving television signals obtained from saidantennas; and diversity switchover controlling means for sending anantenna switchover signal to said receiving means to conduct a diversityswitchover control, wherein said controller further comprises:

synchronizing signal detecting means for detecting a synchronizingsignal of a video signal obtained from said receiving means;

synchronizing signal stabilizing means for stabilizing the detectedsynchronizing signal; and

timing detecting means for detecting a timing of the video signal, onthe basis of the stabilized synchronizing signal, and

said diversity switchover controlling means sends the antenna switchoversignal to said receiving means on the basis of at least the detectedtiming, and conducts the diversity switchover control.

A television receiver of the invention comprises:

antennas of a diversity system for receiving a television wave;

receiving means of the diversity system for receiving television signalsobtained from said antennas;

synchronizing signal detecting means for detecting a synchronizingsignal of a video signal obtained from said receiving means;

synchronizing signal stabilizing means for stabilizing the detectedsynchronizing signal;

timing detecting means for detecting a timing of the video signal on thebasis of the stabilized synchronizing signal;

diversity switchover controlling means for sending an antenna switchoversignal to said receiving means on the basis of at least the detectedtiming to conduct a diversity switchover control;

electric field information detecting means for detecting electric fieldinformation from a signal obtained from said receiving means;

noise predicting means for predicting noises of an audio signal obtainedfrom said receiving means, on the basis of the electric fieldinformation;

noise canceling means for reducing noises of the audio signal, on thebasis of the predicted noises obtained from said noise predicting meansand the electric field information;

audio signal reproducing means for reproducing an audio signal outputfrom said noise canceling means;

display controlling means for controlling a display of the video signalobtained from said receiving means, by using the stabilizedsynchronizing signal; and

displaying means for displaying a signal output from said displaycontrolling means.

A television receiver of the invention comprises:

antennas of a diversity system for receiving a television wave;

receiving means of the diversity system for receiving television signalsobtained from said antennas;

synchronizing signal detecting means for detecting a synchronizingsignal of a video signal obtained from said receiving means;

synchronizing signal stabilizing means for stabilizing the detectedsynchronizing signal;

timing detecting means for detecting a timing of the video signal on thebasis of the stabilized synchronizing signal;

diversity switchover controlling means for sending an antenna switchoversignal to said receiving means on the basis of at least the detectedtiming to conduct a diversity switchover control;

display controlling means for controlling a display of the video signalobtained from said receiving means, by using the stabilizedsynchronizing signal; and

displaying means for displaying a signal output from said displaycontrolling means.

A synchronizing signal stabilizer of the invention comprises:

synchronizing signal detecting means for detecting a synchronizingsignal of an input video signal;

horizontal synchronization phase detecting means for detecting a phaseof a horizontal synchronizing signal of the synchronizing signalobtained from said synchronizing signal detecting means;

horizontal synchronization phase distribution calculating means forobtaining a distribution of the detected phase of the horizontalsynchronizing signal;

horizontal synchronization phase estimating means for estimating thephase of the horizontal synchronizing signal, by using the obtaineddistribution of the phase of the horizontal synchronizing signal; and

synchronizing signal outputting means for outputting a stabilizedsynchronizing signal on the basis of the estimated phase of thehorizontal synchronizing signal.

A synchronizing signal stabilizer of the invention comprises:

synchronizing signal detecting means for detecting a synchronizingsignal of an input video signal;

horizontal synchronization phase detecting means for detecting a phaseof a horizontal synchronizing signal of the synchronizing signalobtained from said synchronizing signal detecting means;

horizontal synchronization phase distribution calculating means forobtaining a distribution of the detected phase of the horizontalsynchronizing signal;

horizontal synchronization phase estimating means for estimating thephase of the horizontal synchronizing signal, by using the obtaineddistribution of the phase of the horizontal synchronizing signal;

vertical synchronization phase detecting means for detecting a phase ofa vertical synchronizing signal of the synchronizing signal obtainedfrom said synchronizing signal detecting means;

vertical synchronization phase distribution calculating means forobtaining a distribution of the detected phase of the verticalsynchronizing signal;

vertical synchronization phase estimating means for estimating the phaseof the vertical synchronizing signal, by using the obtained distributionof the phase of the vertical synchronizing signal; and

synchronizing signal outputting means for outputting a stabilizedsynchronizing signal on the basis of the estimated phase of thehorizontal synchronizing signal and the estimated phase of the verticalsynchronizing signal.

A synchronizing signal stabilizer of the invention comprises:

synchronizing signal detecting means for detecting a synchronizingsignal of an input video signal;

synchronizing signal stabilizing means for stabilizing the synchronizingsignal obtained from said synchronizing signal detecting means;

memory means for storing the stabilized synchronizing signal; and

comparing means for comparing the stored synchronizing signal with thesynchronizing signal obtained from said synchronizing signal detectingmeans, and

when the stabilization is to be conducted, said synchronizing signalstabilizing means utilizes a result of the comparison conducted by saidcomparing means.

A luminance signal stabilizer of the invention comprises

luminance reference signal detecting means for, by using a synchronizingsignal of a video signal included in a received signal, obtaining aluminance reference signal of the video signal;

luminance information calculating means for calculating luminanceinformation from the luminance reference signal, and for holding thecalculated luminance information;

luminance reference signal judging means for judging reliability of theluminance reference signal by using the held luminance information;

luminance reference signal interpolation controlling means forconducting an interpolation generation control of the luminancereference signal on the basis of a result of the judgement; and

luminance reference signal interpolating means for, on the basis of theresult of the judgement, outputting the luminance reference signal withinterpolating the luminance reference signal in accordance withinterpolation information obtained from said luminance reference signalinterpolation controlling means, or outputting the luminance referencesignal without conducting the interpolation.

A color signal stabilizer of the invention comprises:

color reference signal detecting means for, by using a synchronizingsignal of a video signal included in a received signal, obtaining acolor reference signal of the video signal;

color information calculating means for calculating color informationfrom the color reference signal, and for holding the calculated colorinformation;

color reference signal judging means for judging reliability of thecolor reference signal by using the held color information;

color reference signal interpolation controlling means for conducting aninterpolation generation control of the color reference signal on thebasis of a result of the judgement; and

color reference signal interpolating means for, on the basis of theresult of the judgement, outputting the color reference signal withinterpolating the color reference signal in accordance withinterpolation information obtained from said color reference signalinterpolation controlling means, or outputting the color referencesignal without conducting the interpolation.

A video signal stabilizer of the invention comprises: said luminancesignal stabilizer set forth in claim 31; and said color signalstabilizer set forth in claim 37, said stabilizer further comprising:

video signal synthesizing means for synthesizing the video signal, theluminance reference signal output from said luminance reference signalinterpolating means, and the color reference signal output from saidcolor reference signal interpolating means with each other, and foroutputting the synthesized signal.

A video signal stabilizer of the invention comprises:

electric field information detecting means for detecting electric fieldinformation from an input received signal;

a video frame memory which stores a video signal of the received signal;

video signal stabilizing means for conducting a stabilizing process onthe video signal; and

video output controlling means for, by using the electric fieldinformation, selecting one of the video signal obtained from said videosignal synthesizing means, and the video signal obtained from said videoframe memory, and for outputting the selected video signal.

According to the invention, therefore, an abnormality of thesynchronizing signal caused by radio interference such as multipaths orvariation of an electric field is stabilized by the synchronizing signalstabilizing means. A video signal process is then conducted by using thecorrect synchronizing signal which has been stabilized, andsynchronization is stabilized, thereby enabling the abnormality of thevideo signal to be detected. An image is stabilized by the video signalstabilizing means, whereby disturbance of the image can be reduced. Withrespect to an audio signal, noise components contained in the audiosignal are predicted by the noise predicting means, and audio noises arecanceled by the noise canceling means. Therefore, pulsative noises whichare produced in the prior art can be reduced.

A television signal receiver of the invention comprises: receiving meansfor receiving a television signal; pulse detecting means for detecting apulse of a video signal obtained from said receiving means; phasedetecting means for detecting a phase of the detected pulse; videosignal stabilizing means for conducting image-stabilization on the videosignal obtained in said receiving means, on the basis of controlinformation output from said phase detecting means; and displaying meansfor displaying a video signal obtained from said video signalstabilizing means.

A television signal receiver of the invention comprises: receiving meansfor receiving a television signal; pulse detecting means for detecting apulse of a video signal obtained from said receiving means; phasedetecting means for detecting a phase of the detected pulse; ghostdetecting means for detecting a ghost of the video signal; video signalstabilizing means for conducting image-stabilization on the video signalobtained in said receiving means, on the basis of control informationobtained from said phase detecting means and control informationobtained from said ghost detecting means; and displaying means fordisplaying a video signal obtained from said video signal stabilizingmeans.

49. A method of transmitting a television signal in which a controlsignal is inserted into a vertical blanking interval of the televisionsignal.

A television signal receiver of the invention comprises: receiving meansfor receiving a television signal; pulse detecting means for detecting apulse of a video signal obtained from said receiving means; phasedetecting means for detecting a phase of the detected pulse; controlsignal detecting means for detecting a control signal of the televisionsignal; video signal stabilizing means for conductingimage-stabilization on the video signal obtained in said receivingmeans, on the basis of control information obtained from said phasedetecting means and control information obtained from said controlsignal detecting means; and displaying means for displaying a videosignal obtained from said video signal stabilizing means.

A television signal receiver of the invention comprises: receiving meansfor receiving a television signal; synchronizing signal detecting meansfor detecting a synchronizing signal of a video signal obtained fromsaid receiving means; synchronization phase detecting means fordetecting a phase of the synchronizing signal; control signal detectingmeans for detecting a control signal of the television signal; videosignal stabilizing means for conducting image-stabilization on the videosignal obtained in said receiving means, on the basis of controlinformation obtained from said control signal detecting means; anddisplaying means for displaying a video signal obtained from said videosignal stabilizing means.

A television signal receiver of the invention comprises: receiving meansfor receiving a television signal; synchronizing signal detecting meansfor detecting a synchronizing signal of a video signal obtained fromsaid receiving means; synchronization phase detecting means fordetecting a phase of the synchronizing signal; synchronizing signalstabilizing means for stabilizing the synchronizing signal on the basisof phase information obtained from said synchronization phase detectingmeans; control signal detecting means for detecting a control signal ofthe television signal; video signal stabilizing means for conductingimage-stabilization on the video signal obtained in said receivingmeans, on the basis of control information obtained from said controlsignal detecting means and control information obtained from saidsynchronizing signal stabilizing means; and displaying means fordisplaying a video signal obtained from said video signal stabilizingmeans.

A television signal receiver of the invention comprises: receiving meansfor receiving a television signal; synchronizing signal detecting meansfor detecting a synchronizing signal of a video signal obtained fromsaid receiving means; synchronization phase detecting means fordetecting a phase of the synchronizing signal; synchronizing signalstabilizing means for stabilizing the synchronizing signal on the basisof phase information obtained from said synchronization phase detectingmeans; video signal stabilizing means for conducting image-stabilizationon the video signal obtained in said receiving means, on the basis ofcontrol information obtained from said synchronizing signal stabilizingmeans; and displaying means for displaying a video signal obtained fromsaid video signal stabilizing means.

A television signal receiver of the invention comprises: receiving meansfor receiving a television signal; synchronizing signal detecting meansfor detecting a synchronizing signal of a video signal obtained fromsaid receiving means; synchronization phase detecting means fordetecting a phase of the synchronizing signal; synchronizing signalstabilizing means for stabilizing the synchronizing signal on the basisof phase information obtained from said synchronization phase detectingmeans; ghost detecting means for detecting a ghost of the televisionsignal obtained from said receiving means, on the basis of ghostinformation obtained from said synchronization phase detecting means;video signal stabilizing means for conducting image-stabilization on thevideo signal obtained in said receiving means, on the basis of ghostcontrol information obtained from said ghost detecting means and controlinformation obtained from said synchronizing signal stabilizing means;and displaying means for displaying a video signal output from saidvideo signal stabilizing means.

A television signal receiver of the invention comprises: receiving meansfor receiving a television signal; synchronizing signal detecting meansfor detecting a synchronizing signal of a video signal obtained fromsaid receiving means; synchronization phase detecting means fordetecting a phase of the synchronizing signal; synchronizing signalstabilizing means for stabilizing the synchronizing signal on the basisof phase information obtained from said synchronization phase detectingmeans; ghost detecting means for detecting a ghost of the televisionsignal obtained from said receiving means, on the basis of ghostinformation obtained from said synchronization phase detecting means;control signal detecting means for detecting a control signal of thetelevision signal; video signal stabilizing means for conductingimage-stabilization on the video signal obtained in said receivingmeans, on the basis of control information obtained from said controlsignal detecting means, ghost control information obtained from saidghost detecting means, and control information obtained from saidsynchronizing signal stabilizing means; and displaying means fordisplaying a video signal output from said video signal stabilizingmeans.

According to the invention, therefore, a television signal into whichthe control signal is inserted is received, whereby abnormality of avideo signal caused by multipaths or the like can be detected.Furthermore, the video signal can be stabilized by the video signalstabilizing means, so that disturbance of an image can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing the configuration of a television video/audiosignal receiver which is an embodiment of the television receiver of theinvention.

FIG. 2 is a view showing the configuration of a television video/audiosignal receiver which is another embodiment of the television receiverof the invention.

FIG. 3 is a view showing the configuration of a television video/audiosignal receiver which is a further embodiment of the television receiverof the invention.

FIG. 4 is a view showing the configuration of a television video/audiosignal receiver which is a further embodiment of the television receiverof the invention.

FIG. 5 is a view showing the configuration of a television video/audiosignal receiver which is a further embodiment of the television receiverof the invention.

FIG. 6 is a view showing the configuration of a television video/audiosignal receiver which is a further embodiment of the television receiverof the invention.

FIG. 7 is a view showing the configuration of a television video/audiosignal receiver which is a further embodiment of the television receiverof the invention.

FIG. 8 is a view showing the configuration of a television video/audiosignal receiver which is a further embodiment of the television receiverof the invention.

FIG. 9(a) is a flowchart showing a method of the diversity switchovercontrol of an antenna diversity controller of the embodiment, and

FIG. 9(b) is a flowchart showing a diversity switchover control routinein the method of the diversity switchover control.

FIG. 10(a) is a flowchart showing another method of the diversityswitchover control of the antenna diversity controller of theembodiment,

FIG. 10(b) is a flowchart showing diversity switchover control routine 2in the other method of the diversity switchover control, and

FIG. 10(c) is a flowchart showing diversity switchover control routine 1in the other method of the diversity switchover control.

FIG. 11 is a view showing the configuration of a television video/audiosignal receiver which is a further embodiment of the television receiverof the invention.

FIG. 12 is a view showing the configuration of another embodiment of theantenna diversity controller of the invention.

FIG. 13 is a view showing the configuration of a television video/audiosignal receiver which is a further embodiment of the television receiverof the invention.

FIG. 14 is a view showing the configuration of a television video/audiosignal receiver which is an embodiment using the synchronizing signalstabilizer of the invention.

FIG. 15 is a view showing timings of detecting the phases of verticaland horizontal synchronizing signals of a video signal in theembodiment.

FIG. 16(a) is a diagrammatic view showing the manner of storing phasedata of a horizontal synchronizing signal H1 in a horizontalsynchronization phase input buffer of the embodiment,

FIG. 16(b) is a diagrammatic view showing the manner of storing phasedata of horizontal synchronizing signals H1 and H2 in the horizontalsynchronization phase input buffer of the embodiment, and

FIG. 16(c) is a diagrammatic view showing the manner of storing latestphase data in the horizontal synchronization phase input buffer of theembodiment.

FIG. 17 is a view showing the configuration of a television video/audiosignal receiver which is another embodiment using the synchronizingsignal stabilizer of the invention.

FIG. 18(a) is a diagrammatic view showing a horizontal synchronizingsignal input table, and

FIG. 18(b) is a diagrammatic view showing a vertical synchronizingsignal input table.

FIG. 19(a) is a diagrammatic view showing horizontal phase frequencytable 1, and

FIG. 19(b) is a diagrammatic view showing horizontal phase frequencytable 2.

FIG. 20(a) is a view of a phase distribution in the case where the wavestrength is sufficiently high and disturbances due to multipaths and thelike less occur,

FIG. 20(b) is a view of a phase distribution in the case where the wavelevel is low,

FIG. 20(c) is a view of a phase distribution in the case wheremultipaths exist, and

FIG. 20(d) is a view of a phase distribution in the case wheremultipaths exist.

FIG. 21 is a view showing the configuration of another embodiment of thesynchronizing signal stabilizer of the invention.

FIG. 22 is a view showing the configuration of a television video/audiosignal receiver which is a further embodiment using the synchronizingsignal stabilizer of the invention.

FIG. 23 is a view diagrammatically showing the configuration of atelevision video/audio signal receiver which is an embodiment using theluminance signal stabilizer of the invention.

FIG. 24 is a view illustrating the interpolation in the embodiment.

FIG. 25 is a view diagrammatically showing the configuration of atelevision video/audio signal receiver which is an embodiment using thecolor signal stabilizer of the invention.

FIG. 26 is a view diagrammatically showing the configuration of atelevision video/audio signal receiver which is an embodiment using theluminance signal stabilizer and the color signal stabilizer of theinvention.

FIG. 27 is a view diagrammatically showing the configuration of atelevision video/audio signal receiver which is another embodiment usingthe luminance signal stabilizer and the color signal stabilizer of theinvention.

FIG. 28 is a view showing the configuration of a television signalreceiver which is an embodiment of the invention.

FIG. 29 is a view showing a phase distribution of pulses in theembodiment.

FIG. 30 is a view showing the configuration of a television signalreceiver which is another embodiment of the invention.

FIG. 31 is a view showing the configuration of a television signalreceiver which is another embodiment of the invention.

FIG. 32 is a view diagrammatically showing a method of transmitting atelevision signal which is an embodiment of the invention.

FIG. 33 is a view diagrammatically showing a method of transmitting atelevision signal which is another embodiment of the invention.

FIG. 34 is a view diagrammatically showing a method of transmitting atelevision signal which is another embodiment of the invention.

FIG. 35 is a view showing the configuration of a television signalreceiver which is another embodiment of the invention.

FIG. 36 is a view showing the configuration of a television signalreceiver which is another embodiment of the invention.

FIG. 37 is a view showing the configuration of a television signalreceiver which is another embodiment of the invention.

FIG. 38 is a view showing the configuration of a television signalreceiver which is another embodiment of the invention.

FIG. 39 is a view showing the configuration of a television signalreceiver which is another embodiment of the invention.

FIG. 40 is a view showing the configuration for reception in a cartelevision set of the prior art.

DESCRIPTION OF THE REFERENCE NUMERALS

1 antenna

2 receiving means

3 synchronizing signal detecting means

4 synchronizing signal stabilizing means

5 display controlling means

6 displaying means

7 electric field information detecting means

8 video signal stabilizing means

9 diversity switchover controlling means

10 timing detecting means

11 noise predicting means

12 noise canceling means

13 audio signal reproducing means

100 antenna diversity controller

401 horizontal synchronization phase detecting means

402 horizontal synchronization phase distribution calculating means

403 horizontal synchronization phase estimating means

408 horizontal synchronization phase input buffer

404 vertical synchronization phase detecting means

405 vertical synchronization phase distribution calculating means

406 vertical synchronization phase estimating means

409 vertical synchronization phase input buffer

407 synchronizing signal outputting means

801 luminance reference signal detecting means

804 luminance information calculating means

802 luminance reference signal judging means

803 pedestal clamp interpolation controlling means

821 color reference signal detecting means

822 color reference signal judging means

824 color information calculating means

310 receiving means

302 pulse detecting means

303 phase detecting means

304 ghost detecting means

305 video signal stabilizing means

306 displaying means

307 control signal detecting means

310 vertical blanking interval

311 video signal interval

312 anterior equalizing pulse interval

313 vertical synchronizing signal interval

314 posterior equalizing pulse interval

315 reserve video signal interval

316 video signal interval

81 synchronizing signal detecting means

82 synchronization phase detecting means

83 synchronizing signal stabilizing means

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the invention will be described withreference to the drawings.

(Embodiment 1)

FIG. 1 is a view showing the configuration of a television video/audiosignal receiver which is an embodiment of the television receiver of theinvention.

The configuration of the embodiment will be described with reference tothe figure. An antenna 1 receives a television wave, and receiving means2 receives a television signal obtained from the antenna 1.Synchronizing signal detecting means 3 detects a synchronizing signal ofa video signal obtained from the receiving means 2, and synchronizingsignal stabilizing means 4 stabilizes the synchronizing signal obtainedfrom the synchronizing signal detecting means 3, on the basis ofelectric field information obtained from electric field informationdetecting means 7 which will be described later. Display controllingmeans 5 controls a display of the video signal obtained from thereceiving means 2, by using the synchronizing signal obtained from thesynchronizing signal stabilizing means. 4, and displaying means 6displays a signal output from the display controlling means 5. Theelectric field information detecting means 7 detects electric fieldinformation from a signal obtained from the receiving means 2, and videosignal stabilizing means 8 stabilizes the video signal obtained from thereceiving means 2 by using the synchronizing signal obtained from thesynchronizing signal stabilizing means 4 and the electric fieldinformation obtained from the electric field information detecting means7, and outputs the stabilized video signal. Noise predicting means 11predicts noises of an audio signal obtained from the receiving means 2,on the basis of the electric field information obtained from theelectric field information detecting means 7. Noise canceling means 12reduces noises of the audio signal, on the basis of the predicted noisesobtained from the noise predicting means 11 and the electric fieldinformation obtained from the electric field information detecting means7. Audio signal reproducing means 13 reproduces an audio signal outputfrom the noise canceling means 12.

The operation of the thus configured embodiment will be described withreference to FIG. 1.

A video signal wave is obtained by the antenna 1 which is one kind ofinputting means for a video signal, and the obtained signal is thentransmitted to the receiving means 2. In the receiving means 2, a videosignal and an audio signal are detected from a television signal, and,for example, an IF signal is generated as a control signal for detectingelectric field information. The synchronizing signal detecting means 3detects a vertical synchronizing signal and a horizontal synchronizingsignal from the video signal and transmits the signals to thesynchronizing signal stabilizing means.

On the other hand, in the electric field information detecting means 7,electric field information such as the state of multipaths of thereceived wave, the electric field strength, and variation of theelectric field strength is detected from the control signal obtainedfrom the receiving means 2.

The synchronizing signal stabilizing means 4 conducts a stabilizingprocess on the synchronizing signal obtained in the synchronizing signaldetecting means, on the basis of the electric field information obtainedin the electric field information detecting means 7. In this process,for example, a synchronizing signal of an abnormal phase is deleted, amissing synchronizing signal is interpolated, and the pulse width of asynchronizing signal is improved.

The video signal stabilizing means 8 conducts a stabilizing process onthe video signal obtained from the receiving means 2 by using thesynchronizing signal obtained from the synchronizing signal stabilizingmeans 4. The stabilizing process includes generation of a luminancesignal by interpolation, generation of a color signal by interpolation,and replacement of an image. After the stabilizing process, the videosignal is output. In the embodiment, specifically, objects which are tobe stabilized by the video signal stabilizing means 8 include aluminance signal, a color signal, ghosts, and an image skip.

In the display controlling means 5, a signal appropriate for thedisplaying means 6 is generated from the video signal obtained from thevideo signal stabilizing means 8, by using the synchronizing signalobtained from the synchronizing signal stabilizing means 4, and thegenerated signal is supplied to the displaying means 6.

On the other hand, with respect to the audio signal obtained from thereceiving means 2, noise components contained in the signal arepredicted by the noise predicting means 11. When the electric fieldinformation is used in the prediction, it is possible to accuratelypredict the noise components. In the noise canceling means 12, a noisecanceling process which uses the noise signal obtained from the noisepredicting means 11 and corresponds to the electric field information isconducted on the audio signal obtained from the receiving means 2. Theresult of the process is output. The spectrum subtraction process or thefiltering process may be used as the noise canceling process. The audiosignal which has undergone the noise canceling process is output by theaudio signal reproducing means 13.

As a result, the stabilized video signal, and the audio signal in whichnoises are reduced can be obtained.

In the above, the embodiment which is a receiver having video signalstabilizing means has been described. The invention is not restricted tothis. As shown in FIG. 2, for example, a configuration in which videosignal stabilizing means is not disposed may be employed. FIG. 2 is aview showing the configuration of a television video/audio signalreceiver as another example in which the video signal stabilizing means8 of the television video/audio signal receiver shown in FIG. 1 is notdisposed. As shown in the figure, the television video/audio signalreceiver comprises: receiving means 2 for receiving a television signal;synchronizing signal detecting means 3 for detecting a synchronizingsignal of a video signal obtained from the receiving means 2; electricfield information detecting means 7 for detecting electric fieldinformation from a signal obtained from the receiving means 2;synchronizing signal stabilizing means 4 for stabilizing thesynchronizing signal obtained from the synchronizing signal detectingmeans 3, on the basis of the electric field information obtained fromthe electric field information detecting means 7; display controllingmeans 5 for controlling a display of the video signal obtained from thereceiving means 2, by using the synchronizing signal obtained from thesynchronizing signal stabilizing means 4; and displaying means 6 fordisplaying a signal output from the display controlling means 5. Thetelevision video/audio signal receiver further comprises: noisepredicting means 11 for predicting noises of an audio signal obtainedfrom the receiving means 2, on the basis of the electric fieldinformation obtained from the electric field information detecting means7; noise canceling means 12 for reducing noises of the audio signal, onthe basis of the predicted noises obtained from the noise predictingmeans 11 and the electric field information obtained from the electricfield information detecting means 7; and audio signal reproducing means13 for reproducing an audio signal output from the noise canceling means12. The embodiment can attain effects which are substantially identicalwith those of the embodiment described above.

In the above, the embodiment in which the noise canceling process isconducted on an audio signal has been described. The invention is notrestricted to this. As shown in FIG. 3, for example, a configuration inwhich noise predicting means, noise canceling means, and audio signalreproducing means are not disposed may be employed. FIG. 3 is a viewshowing the configuration of a television video/audio signal receiver asa further example in which the noise predicting means 11, the noisecanceling means 12, and the audio signal reproducing means 13 of thetelevision video/audio signal receiver shown in FIG. 1 are not disposed.As shown in the figure, the television video/audio signal receivercomprises: receiving means 2 for receiving a television signal;synchronizing signal detecting means 3 for detecting a synchronizingsignal of a video signal obtained from the receiving means 2;synchronizing signal stabilizing means 4 for stabilizing thesynchronizing signal obtained from the synchronizing signal detectingmeans 3; video signal stabilizing means 8 for stabilizing the videosignal obtained from the receiving means 2, and for outputting thestabilized video signal; display controlling means 5 for controlling adisplay of the stabilized video signal output from the video signalstabilizing means 8, by using the synchronizing signal obtained from thesynchronizing signal stabilizing means 4; and displaying means 6 fordisplaying a signal output from the display controlling means 5. Thetelevision video/audio signal receiver further comprises electric fieldinformation detecting means 7 for detecting electric field informationfrom a signal obtained from the receiving means 2. The synchronizingsignal stabilizing means 4 stabilizes the synchronizing signal, on thebasis of the electric field information obtained from the electric fieldinformation detecting means 7, and the video signal stabilizing means 8stabilizes the video signal by using the synchronizing signal obtainedfrom the synchronizing signal stabilizing means 4 and the electric fieldinformation obtained from the electric field information detecting means7. The embodiment can attain effects which are substantially identicalwith those of the embodiment described above, except that noises of theaudio signal cannot be reduced.

In the above, the embodiment in which electric field information of areceived signal is used has been described. The invention is notrestricted to this. As shown in FIG. 4, for example, a configuration inwhich electric field information detecting means is not disposed may beemployed. FIG. 4 is a view showing the configuration of a televisionvideo/audio signal receiver as a further example in which the electricfield information detecting means 7 of the television video/audio signalreceiver shown in FIG. 3 is not disposed. As shown in the figure, thetelevision video/audio signal receiver comprises: receiving means 2 forreceiving a television signal; synchronizing signal detecting means 3for detecting a synchronizing signal of a video signal obtained from thereceiving means 2; synchronizing signal stabilizing means 4 forstabilizing the synchronizing signal obtained from the synchronizingsignal detecting means 3; video signal stabilizing means 8 forstabilizing the video signal obtained from the receiving means 2, andfor outputting the stabilized video signal; display controlling means 5for controlling a display of the stabilized video signal output from thevideo signal stabilizing means 8, by using the synchronizing signalobtained from the synchronizing signal stabilizing means 4; anddisplaying means 6 for displaying a signal output from the displaycontrolling means 5. The video signal stabilizing means 8 stabilizes thevideo signal by using the synchronizing signal obtained from thesynchronizing signal stabilizing means 4. The embodiment can attaineffects which are substantially identical with those of the embodimentdescribed above except that electric field information cannot beutilized in the various stabilizing processes.

In the above, the embodiment in which, in the process of stabilizing thevideo signal obtained from the receiving means 2, the video signalstabilizing means uses the synchronizing signal obtained in thesynchronizing signal stabilizing means 4 has been described. Theinvention is not restricted to this. As shown in FIG. 5, for example, aconfiguration in which the synchronizing signal obtained in thesynchronizing signal stabilizing means 4 is not used may be employed.FIG. 5 is a view showing the configuration of a television video/audiosignal receiver as a further example in which the output of thesynchronizing signal stabilizing means 4 of the television video/audiosignal receiver shown in FIG. 4 is not sent to the video signalstabilizing means 8. As shown in the figure, the television video/audiosignal receiver comprises: receiving means 2 for receiving a televisionsignal; synchronizing signal detecting means 3 for detecting asynchronizing signal of a video signal obtained from the receiving means2; synchronizing signal stabilizing means 4 for stabilizing thesynchronizing signal obtained from the synchronizing signal detectingmeans 3; video signal stabilizing means 8 for stabilizing the videosignal obtained from the receiving means 2, and for outputting thestabilized video signal; display controlling means 5 for controlling adisplay of the stabilized video signal output from the video signalstabilizing means 8, by using the synchronizing signal obtained from thesynchronizing signal stabilizing means 4; and displaying means 6. fordisplaying a signal output from the display controlling means 5. Theembodiment can attain effects which are substantially identical withthose of the embodiment described above except that the synchronizingsignal cannot be utilized in the process of stabilizing the video signalin video signal stabilizing means.

In the above, the embodiment which is a receiver having video signalstabilizing means has been described. The invention is not restricted tothis. As shown in FIG. 6, for example, a configuration in which videosignal stabilizing means is not disposed may be employed. FIG. 6 is aview showing the configuration of a television video/audio signalreceiver as a further example in which the video signal stabilizingmeans 8 of the television video/audio signal receiver shown in FIG. 3 isnot disposed. As shown in the figure, the television video/audio signalreceiver comprises: receiving means 2 for receiving a television signal;synchronizing signal detecting means 3 for detecting a synchronizingsignal of a video signal obtained from the receiving means 2; electricfield information detecting means 7 for detecting electric fieldinformation from a signal obtained from the receiving means 2;synchronizing signal stabilizing means 4 for stabilizing thesynchronizing signal obtained from the synchronizing signal detectingmeans 3, on the basis of the electric field information obtained fromthe electric field information detecting means 7; display controllingmeans 5 for controlling a display of the video signal obtained from thereceiving means 2, by using the synchronizing signal obtained from thesynchronizing signal stabilizing means 4; and displaying means 6 fordisplaying a signal output from the display controlling means 5. Theembodiment can attain effects which are substantially identical withthose of the embodiment described above, except that the process ofstabilizing the video signal is not conducted.

In the above, the embodiment which is a receiver having electric fieldinformation detecting means has been described. The invention is notrestricted to this. As shown in FIG. 7, for example, a configuration inwhich electric field information detecting means is not disposed may beemployed. Also in this case, it is possible to attain effects which aresubstantially identical with those of the embodiment described above,except that electric field information cannot be utilized in astabilizing process of synchronizing signal stabilizing means. FIG. 7 isa view showing the configuration of a television video/audio signalreceiver as a further example in which the electric field informationdetecting means 7 of the television video/audio signal receiver shown inFIG. 6 is not disposed. As shown in the figure, the televisionvideo/audio signal receiver comprises: receiving means 2 for receiving atelevision signal; synchronizing signal detecting means 3 for detectinga synchronizing signal of a video signal obtained from the receivingmeans; synchronizing signal stabilizing means 4 for stabilizing thesynchronizing signal obtained from the synchronizing signal detectingmeans 3; display controlling means 5 for controlling a display of thevideo signal obtained from the receiving means 2, by using thesynchronizing signal obtained from the synchronizing signal stabilizingmeans 4; and liquid crystal displaying means 6 for conducting a liquidcrystal display of a signal output from the display controlling means 5.In this case, RGB signals must be supplied for each dot of the liquidcrystal displaying means in order to conduct a liquid crystal display,and the timing of outputting each of the RGB signals is predetermined.The display controlling means 5 generates output timing pulsescorresponding to the output timing of each of the RGB signals, on thebasis of the stabilized synchronizing signal, and supplies the pulses tothe liquid crystal displaying means 6. Also in the embodiment, astabilized image can be obtained by generating the timing pulses on thebasis of the stabilized synchronizing signal.

(Embodiment 2)

FIG. 8 is a view showing the configuration of a television video/audiosignal receiver which is an embodiment of the television receiver of theinvention.

The configuration of the embodiment will be described with reference tothe figure. The components which are fundamentally identical with thosedescribed with reference to FIG. 1 are designated by the same referencenumerals, and their description is omitted.

As shown in the figure, the television video/audio signal receivercomprises an antenna diversity controller 100, video signal stabilizingmeans 8, display controlling means 5, and displaying means 6. Theantenna diversity controller 100 comprises diversity antennas 1,receiving means 2, synchronizing signal detecting means 3, synchronizingsignal stabilizing means 4, electric field information detecting means7, diversity switchover controlling means 9, and timing detecting means10.

The synchronizing signal stabilizing means 4 stabilizes vertical andhorizontal synchronizing signals which are detected by the synchronizingsignal detecting means 3 from a video signal obtained in the receivingmeans 2, and outputs the stabilized synchronizing signals. The timingdetecting means 10 determines a diversity switchover enable period basedon the synchronizing signal stabilized by the synchronizing signalstabilizing means 4.

FIGS. 9(a) and 9(b) are flowcharts showing the method of controlling thediversity switchover in the antenna diversity controller of theembodiment.

As shown in FIG. 9(a), in step S101, the diversity switchover enableperiod obtained in the timing detecting means 10 is used for judgingwhether the diversity switchover control is to be conducted or not. Thediversity switchover enable period is the vertical synchronizationinterval, a period including the vertical synchronization interval, or aperiod before and after the vertical synchronization interval.

If the current process timing is in the diversity switchover enableperiod, the diversity switchover control process is conducted (stepS102). In order to transfer the control to the process, a loopconfiguration such as that shown in FIG. 9(a), or an interrupt processbased on the diversity switchover enable period may be used.

As shown in FIG. 9(b), in a diversity switchover control routine, anantenna switchover signal is sent to the receiving means 2 (step S201),the antenna 1 is switched to another one, and electric field informationrelating to the wave obtained from the new antenna is input (step S202).This operation is conducted on each of the diversity antennas (stepS203), so that electric field information of the waves received by allthe antennas is obtained. When the antenna scanning (step S203) isended, the obtained electric field information of the antennas isanalyzed, and the optimum antenna is selected (step S204). Then, theantenna connection is switched to the selected optimum antenna (stepS205). Thereafter, the wave input using the new antenna is conducteduntil the diversity switchover control (step S102) is next done.

In the judgment in step S203 on the end of the antenna scanning, thefact whether information of all the antennas has been obtained or not,or that whether the operation including the antenna switchover entersthe diversity switchover enable period or not is used as the criterion.

For each of the antennas, therefore, one or plural sets of electricfield information may be obtained. In the case where plural sets ofelectric field information are obtained, the average value, the minimumvalue, or the maximum value of the electric field information may beused.

The selection of the optimum antenna in step S204 may be conducted inthe following manner. An antenna from which the highest electric fieldstrength is obtained, or that in which multipaths are minimum may beselected. In this case, it is possible to accurately select the optimumantenna. An antenna from which variation of multipaths or the electricfield is small may be selected by using information relating tovariation of multipaths or the electric field. In order to prevent theantenna switchover control from being frequently conducted, a method maybe employed in which information of antennas which have been selected ispreviously stored, information of a newly selected antenna is comparedwith the stored information, and finally the optimum antenna is selectedby using a threshold of the electric field information, the multipathstrength, or the like. A control may be conducted in such a manner thatan antenna in which the electric field strength is higher than apredetermined value is not selected, or that, when multipaths frequentlyoccur, the switchover of the antennas is positively conducted. Themethod of selecting the optimum antenna will be described later indetail.

Next, an example in which another diversity switchover control isconducted in the above-described configuration will be described withreference to flowcharts shown in FIGS. 10(a) to 10(c).

As shown in FIG. 10(a), in steps S303 and S301, diversity switchoverenable periods 1 and 2 obtained in the timing detecting means 10 areused for judging whether the diversity switchover control is to beconducted or not. The diversity switchover enable period 1 is thevertical synchronization interval, a period including the verticalsynchronization interval, or a period before and after the verticalsynchronization interval. The diversity switchover enable period 2 isthe horizontal synchronization interval, a period including thehorizontal synchronization interval, or a period before and after thehorizontal synchronization interval. The first diversity switchoverenable period of the invention corresponds to the diversity switchoverenable period 1, and the second diversity switchover enable period ofthe invention corresponds to the diversity switchover enable period 2.

If the current process timing is in the diversity switchover enableperiod 1 or 2, a diversity switchover control process 1 or 2 isconducted (step S304 or S302). In order to transfer the control to theprocess, a loop configuration such as that shown in FIG. 10(a), or aninterrupt process based on the diversity switchover enable period may beused.

As shown in FIG. 10(b), in a diversity switchover control routine 2, anantenna switchover signal is sent to the receiving means 2 (step S201),the antenna 1 is switched to another one, and electric field informationrelating to the wave obtained from the new antenna is input (step S202).On the basis of the thus obtained electric field information, thedistribution of the electric field information of each antenna isobtained (step S401). This operation is conducted until the antennascanning is ended (step S203).

In the judgment in step S203 on the end of the antenna scanning, thefact whether information of all the antennas has been obtained or not,or that whether the operation including the antenna switchover entersthe diversity switchover enable period 2 or not is used as thecriterion.

Then, the optimum antenna in the diversity switchover control routine 2is selected (step S204), and the antenna connection is switched to theselected optimum antenna (step S205). In this case, the selection of theoptimum antenna may be conducted so as to select the antenna selectedbefore the control enters the diversity switchover control routine 2(step S302). This substantially results in that the antenna selected indiversity switchover control routine 1 (step S304) is used. Therefore,the antenna switchover can be conducted for each image frame. When theantenna selection is conducted on the basis of the electric fielddistribution obtained in step S401 (step S204), the optimum antenna canbe selected for each line or for each horizontal synchronizing signal.

As shown in FIG. 10(c), the same process as that of the diversityswitchover control routine 2 is conducted in the diversity switchovercontrol routine 1.

As described above, in the selection method of the embodiment, theoptimum antenna is determined on the basis of the electric fieldinformation distribution. Hereinafter, the electric field informationdistribution used in the process will be described in more detail.

As the electric field information distribution, used is the electricfield strength signal, a multipath level signal, or variation of such asignal. The distribution may have a form of a histogram, the maximumvalue, the minimum value, or the like. In the case where a histogram ofthe electric field strength or the multipath level is used, a histogramof the electric field strength of a certain antenna is prepared, theelectric field strength or the multipath level of the maximum frequencymay be used as the representative value for selecting the optimumantenna.

An antenna such as that i n which the electric field strength ishighest, that in which multipaths are minimum, or that in which theelectric field variation and the multipath variation are small may beselected as the optimum antenna. When the multipath level is high, thefollowability can be improved by positively switching the antennas. Whenthe electric field strength is high or less varied, a stabilizedreception state can be obtained by suppressing the switchover of theantennas.

As described above, according to the embodiment, the diversityswitchover is conducted by using a stabilized synchronizing signal andcontrolled by using electric field information, and hence it is possibleto select an antenna of reduced multipath interference. As a result,multiple images can be reduced and an image which is further stabilizedcan be obtained.

In the embodiment, a noise canceling process for an audio signal is notconsidered. It is more preferable to form a configuration which canconduct a noise canceling process as shown in FIG. 11. FIG. 11 is a viewshowing the configuration of a television video/audio signal receiver ofanother embodiment in which the configuration of the televisionvideo/audio signal receiver shown in FIG. 8 is further provided with:noise predicting means 11 for predicting noises of an audio signalobtained from the receiving means 2, on the basis of the electric fieldinformation obtained from the electric field information detecting means7; noise canceling means 12 for reducing noises of the audio signal, onthe basis of the predicted noises obtained from the noise predictingmeans 11 and the electric field information; and audio signalreproducing means 13 for reproducing an audio signal output from thenoise canceling means 12. In the configuration, when noises of the audiosignal are to be predicted, the noise predicting means 11 utilizes alsothe antenna switchover signal, and, when noises are to be reduced, thenoise canceling means 12 utilizes also the antenna switchover signal.

Next, the method of utilizing the antenna switchover signal in the noisecancellation will be described.

In the audio detection, the antenna switchover control causes adiscontinuous signal to be superimposed on the audio signal, with theresult that audio noises are generated. When the antenna switchoversignal is utilized, it is possible to identify the location where noisesenter the audio signal. Therefore, noises can be reduced by conductingthe noise canceling process on the specified location. Noises may becanceled by a method in which, when an antenna switchover occurs,predicted noises are generated and then the noise canceling process isconducted. Since the location of noises can be identified, interpolationmay be performed by using the waveform appearing before noises aregenerated.

According to this configuration, also a noise canceling process for anaudio signal is conducted, and hence an effect that it is possible toreproduce an audio signal in which noises are further reduced isattained in addition to the above-mentioned effects.

In the above, the embodiment in which the antenna diversity controller100 comprises electric field information detecting means has beendescribed. The invention is not restricted to this. As shown in FIG. 12,for example, an antenna diversity controller 101 having a configurationin which electric field information detecting means is not disposed maybe used in place of the antenna diversity controller 100. The antennadiversity controller 101 shown in FIG. 12 comprises: antennas 1 of adiversity system for receiving a television wave; receiving means 2 ofthe diversity system for receiving television signals obtained from theantennas 1; synchronizing signal detecting means 3 for detecting asynchronizing signal of a video signal obtained from the receiving means2; synchronizing signal stabilizing means 4 for stabilizing thesynchronizing signal obtained from the synchronizing signal detectingmeans 3; timing detecting means 10 for detecting a timing of the videosignal, on the basis of the stabilized synchronizing signal; anddiversity switchover controlling means 9 for sending an antennaswitchover signal to the receiving means 2 on the basis of the detectedtiming and a signal level obtained from the receiving means 2. In thiscase, the timing detected by the timing detecting means is a timing of avertical synchronizing signal of the video signal, the timing detectingmeans determines a diversity switchover enable period based on thetiming of the vertical synchronizing signal, and, during the determineddiversity switchover enable period, the diversity switchover controllingmeans sends the antenna switchover signal to the receiving means andconducts the diversity switchover control of switching to an optimumantenna. According to this configuration, the diversity switchover canbe controlled by using the stabilized synchronizing signal, and astabilized image can be obtained while preventing the antennas frombeing switched over during one image frame. A configuration differentfrom the above may be employed as follows. In FIG. 12, for example, thedetection timing of the timing detecting means includes a timing of avertical synchronizing signal of the video signal and that of ahorizontal synchronizing signal. The timing detecting means determines afirst diversity switchover enable period based on the timing of thevertical synchronizing signal and a second diversity switchover enableperiod based on the timing of the horizontal synchronizing signal.During the determined first or second diversity switchover enableperiod, the diversity switchover controlling means sends the antennaswitchover signal to the receiving means and conducts the diversityswitchover control of switching to an optimum antenna. According to thisconfiguration, the use of the stabilized synchronizing signal allows theantennas to be sampled also during the horizontal synchronizationinterval, and hence the diversity antennas can be prevented from beingerroneously switched over, with the result that a further stabilizedimage can be obtained. In addition to the configuration, for example, aconfiguration may be employed in which, when the control of switching toan optimum antenna is to be conducted, the diversity switchovercontrolling means obtains the signal level distribution of each of theantennas during the second diversity switchover enable period, andutilizes the obtained distribution. According to this configuration, thesignal level distribution (electric field information distribution)relating to each of the antennas is obtained, and hence a furtherstabilized antenna can be selected, thereby enabling the diversityswitchover to be correctly conducted. Therefore, it is possible toobtain an image which is further stabilized. Moreover, the diversityantenna switching control can be conducted more finely, and hence thefollowability for radio interference can be improved.

In the above, the embodiment in which the antenna diversity controller101 is used in place of the antenna diversity controller 100 and whichis provided with the video signal stabilizing means 8, the displaycontrolling means 5, and the displaying means 6 has been described. Theinvention is not restricted to this. As shown in FIG. 13, for example, aconfiguration in which video signal stabilizing means is not providedmay be employed. Another embodiment of a television video/audio signalreceiver shown in FIG. 13 comprises: antennas 1 of a diversity systemfor receiving a television wave; receiving means 2 of the diversitysystem for receiving television signals obtained from the antennas 1;synchronizing signal detecting means 3 for detecting a synchronizingsignal of a video signal obtained from the receiving means 2;synchronizing signal stabilizing means 4 for stabilizing thesynchronizing signal obtained from the synchronizing signal detectingmeans 3; timing detecting means 10 for detecting a timing of the videosignal, on the basis of the stabilized synchronizing signal; diversityswitchover controlling means 9 for sending an antenna switchover signalto the receiving means 2 on the basis of the detected timing and thesignal level obtained from the receiving means 2 to conduct a diversityswitchover control; display controlling means 5 for controlling adisplay of the video signal obtained from the receiving means 2, byusing the stabilized synchronizing signal; and displaying means 6 fordisplaying a signal output from the display controlling means 5. Theembodiment can attain effects which are substantially identical withthose of the embodiment described with reference to FIG. 12, except thatthe process of stabilizing the video signal by means of the video signalstabilizing means is not conducted.

(Embodiment 3)

FIG. 14 is a view showing the configuration of a television video/audiosignal receiver which is an embodiment using the synchronizing signalstabilizer of the invention.

The configuration of the embodiment will be described with reference tothe figure. The components which are fundamentally identical with thosedescribed with reference to FIGS. 7 and 13, and the like are designatedby the same reference numerals. Hereinafter, synchronizing signalstabilizing means 4 (synchronizing signal stabilizer) will be mainlydescribed.

As shown in FIG. 14, the synchronizing signal stabilizing means 4comprises horizontal synchronization phase detecting means 401,horizontal synchronization phase distribution calculating means 402,horizontal synchronization phase estimating means 403, a horizontalsynchronization phase input buffer 408, vertical synchronization phasedetecting means 404, vertical synchronization phase distributioncalculating means 405, vertical synchronization phase estimating means406, a vertical synchronization phase input buffer 409, andsynchronizing signal outputting means 407. The horizontalsynchronization phase detecting means 401 detects the phase of ahorizontal synchronizing signal of the synchronizing signals obtainedfrom synchronizing signal detecting means 3, and the horizontalsynchronization phase distribution calculating means 402 obtains thedistribution of the phase of the horizontal synchronizing signalobtained by the horizontal synchronization phase detecting means 401.The horizontal synchronization phase estimating means 403 estimates thephase of the horizontal synchronizing signal, by using the distributionof the phase of the horizontal synchronizing signal obtained from thehorizontal synchronization phase distribution calculating means 402. Thehorizontal synchronization phase input buffer 408 stores phases ofhorizontal synchronizing signals obtained from the horizontalsynchronization phase detecting means 401, the vertical synchronizationphase detecting means 404 detects the phase of a vertical synchronizingsignal of the synchronizing signals obtained from the synchronizingsignal detecting means 3, and the vertical synchronization phasedistribution calculating means 405 obtains the distribution of the phaseof the vertical synchronizing signal obtained by the verticalsynchronization phase detecting means 404. The vertical synchronizationphase estimating means 406 estimates the phase of the verticalsynchronizing signal, by using the distribution of the phase of thevertical synchronizing signal obtained from the vertical synchronizationphase distribution calculating means 405. The vertical synchronizationphase input buffer 409 stores phases of vertical synchronizing signalsobtained from the vertical synchronization phase detecting means 404.The synchronizing signal outputting means 407 outputs a stabilizedsynchronizing signal from the detected synchronizing signal, on thebasis of the estimated phase of the horizontal synchronizing signal andthe estimated phase of the vertical synchronizing signal. The embodimentfurther comprises: clock signal generating means 14; and a counter 15which detects the phase of each synchronizing signal which will bedescribed later, as a counter value by using a clock signal obtainedfrom the clock signal generating means 14. The horizontalsynchronization phase distribution calculating means 402 and thevertical synchronization phase distribution calculating means 405 areconfigured so as to obtain the frequency of the phase of eachsynchronizing signal, by using the counter value obtained by the counter15.

The operation of the thus configured embodiment will be described withreference to the drawings.

The horizontal synchronization phase detecting means 401 detects thephase of a horizontal synchronizing signal which passes through thereceiving means 2 and is then output from the synchronizing signaldetecting means 3.

As the phase, used is the counter value of the counter 15 (or a timer)of a period which is equal to the horizontal synchronization interval,i.e., the 1 H period or similar to the period, or that of a counter ofan arbitrary period. In the case of a counter of an arbitrary period,the difference between the arbitrary period and the period of thehorizontal synchronization is previously known, and the counter value isused while being corrected on the basis of the difference.

Hereinafter, the case of the counter 15 of the 1 H period will bedescribed. When a horizontal synchronizing signal is input, the countervalue at the timing of the input is set to be an input phase. The inputphase is accumulated in the horizontal synchronization phase inputbuffer 408. The horizontal synchronization phase input buffer 408 storesa specified number of input values. In this case, latest data are usedas the data of the specified number. For this purpose, FIFO or a ringbuffer may be used.

The operation will be described in more detail with reference to FIGS.15 and 16. FIG. 15 is a view illustrating the timings of detecting thephases of vertical and horizontal synchronizing signals of a videosignal. FIG. 16 is a view diagrammatically showing the manner of storingphase data in the horizontal synchronization phase input buffer 408.

As shown in FIG. 15, a received signal 200 in which horizontalsynchronizing signals H₁ to H_(n) exist between vertical synchronizingsignals V₁ and V₂ and the vertical synchronizing signal V₂ is followedby horizontal synchronizing signals H₁, H₂, H₃, H₄, . . . issequentially supplied to the synchronizing signal detecting means 3. Thetimes when the vertical synchronizing signals V₁ and V₂ are detected areindicated by T_(V1), and T_(V2). The counter 15 starts the countoperation at a fixed period or the 1 H period with using T₁ (T_(n+1))when a fixed time has elapsed from the time T_(V1) (T_(V2)) when thevertical synchronizing signal is detected, as the reference. If thevalue of the counter 15 at the time t₁ when the horizontalsynchronization phase detecting means 401 detects the initial horizontalsynchronizing signal H₁ in the fixed interval between the times T₁ to T₂is 50, the counter value is stored in the horizontal synchronizationphase input buffer 408 as shown in FIG. 16(a). If the value of thecounter 15 at the time t₂ when the horizontal synchronization phasedetecting means 401 detects the horizontal synchronizing signal H₂ inthe fixed interval between the times T₂ to T₃ is 70, the counter valueis stored in the horizontal synchronization phase input buffer 408 asshown in FIG. 16(b). The recording operations are sequentially repeated.If the value of the counter 15 at the time t_(j) when the horizontalsynchronizing signal H_(j) is detected in the interval between the timesT_(j) to T_(j+1) is 120, the value at the time t_(j+1) when thehorizontal synchronizing signal H_(j+1) is detected is 100, the value atthe time t_(n−1) when the horizontal synchronizing signal H_(n−1) isdetected is 65, and the value at the time t_(n) when the horizontalsynchronizing signal H_(n) is detected is 60, the counter values for then−j+1 number of latest horizontal synchronizing signals among the nnumber of horizontal synchronizing signals are stored in the horizontalsynchronization phase input buffer 408. The stored contents of thehorizontal synchronization phase input buffer 408 are held for apredetermined period which continues until, for example, the nextvertical synchronizing signal V₂ is detected. The stored contents areused in the estimation of the horizontal synchronization phase whichwill be described later. The estimated horizontal synchronization phaseis used for a synchronizing signal of a frame which is subsequentlysent. After the vertical synchronization phase detecting means 404detects the vertical synchronizing signal TV2 which is subsequentlysent, the counter 15 again starts the count operation in the same manneras described above with using time T_(n+1) as the reference. The countervalue of the latest horizontal synchronizing signal phase is stored inthe horizontal synchronization phase input buffer 408. The n number ofcounter values of the phases of the horizontal synchronizing signals H₁to H_(n) which are detected for each frame are classified intopredetermined classes by the horizontal synchronization phasedistribution calculating means 402 in the manner described later. Thefrequencies of phase data in each class are calculated, and a frequencytable such as a histogram for obtaining the frequency distribution isprepared.

In the above, the operations relating to the horizontal synchronizationphase detecting means 401 have been mainly described. The operationsrelating to the vertical synchronization phase detecting means 404 aresubstantially identical with those described above when the horizontalsynchronizing signal is replaced with the vertical synchronizing signal.Therefore, their detailed description is omitted.

Returning to FIG. 14, the horizontal synchronization phase distributioncalculating means 402 obtains the distribution of the input phases. Asthe distribution, the occurrence probability distribution relating toeach phase in the 1 H period, a histogram of input phases in discretedata, or the like may be used. Next, the horizontal synchronizationphase estimating means 403 estimates the horizontal synchronizationphase, on the basis of the prepared phase distribution and the data ofthe input buffer. In this case, the maximum distribution, for example,the phase of the maximum probability in the probability distribution isselected as the phase of the synchronizing signal. In the histogram, theclass of the maximum frequency is selected. In order to check theselected data, the data is compared with the contents of the inputbuffer. If the contents selected in the horizontal phase distributionexist also in the input buffer, the reliability of the contents selectedin the horizontal phase distribution is high. Therefore, the phase isused as an estimated value. In the case where a histogram is used as thephase distribution, since each class has a substantial width, a data inthe vicinity of the maximum frequency of the histogram is selected fromthe data of the input buffer. In this case, an average value, a median,or the like of data included in a class in the vicinity of the maximumfrequency of the histogram may be used from the input buffer. In thecase where values which have been estimated in the past are stored, itis possible also to select a value which is a data of the input bufferestimated in the past and included in the class in the vicinity of themaximum value of the histogram. In this way, the horizontalsynchronization phase is estimated, the estimated phase is transmittedto the synchronizing signal outputting means, and the synchronizingsignal is output. The synchronizing signal outputting means outputs theestimated synchronizing signal. In this case, in place of the phase ofthe synchronizing signal detected by the synchronizing signal detectingmeans 3, the timing of outputting the vertical synchronizing signal maybe used as the timing of outputting the estimated synchronizing signal.This produces an effect that the image is hardly disturbed. The timingmay be based on the timing of outputting the horizontal synchronizationphase. Also in this case, the same effect that the image is hardlydisturbed can be attained.

The estimation of the horizontal synchronization phase in the horizontalsynchronization phase estimating means 403 may be conducted at any time.When timing of the estimation is restricted to one of the followingtimings, the load can be further reduced. Namely, the estimation may beconducted when the horizontal synchronizing signal is input, when thehorizontal synchronizing signal is output, when the verticalsynchronizing signal is input, when the vertical synchronizing signal isoutput, or immediately after the vertical or horizontal synchronizingsignal period is ended.

In the embodiment, the timing when data of the phase distribution ofsynchronizing signals are updated (reset) is not particularly described.As shown in FIG. 17, for example, it is preferable to have timingdetecting means for detecting the timing of the video signal on thebasis of the stabilized synchronizing signal output from thesynchronizing signal outputting means 407.

In such a configuration, the horizontal synchronization phasedistribution calculating means 402 updates the phase distribution byutilizing a timing signal obtained from the timing detecting means 10,and the vertical synchronization phase distribution calculating means405 updates the phase distribution by utilizing the timing signalobtained from the timing detecting means 10. FIG. 17 is a view showingthe configuration of a television video/audio signal receiver of anotherembodiment in which the configuration of the television video/audiosignal receiver shown in FIG. 14 is further provided with the timingdetecting means 10, and electric field information detecting means 7 fordetecting electric field information from a signal obtained from thereceiving means 2. FIG. 17 particularly shows the configuration centeredon synchronizing signal stabilizing means 4 (synchronizing signalstabilizer). According to this configuration, the updation of the dataof the phase distribution of the synchronizing signal can be conductedat the timing when the stabilized vertical synchronizing signal isoutput, or that when the stabilized horizontal synchronization phase isoutput. Consequently, this produces an effect that the image is furtherhardly disturbed.

The calculation result of the horizontal synchronization phasedistribution obtained by the horizontal synchronization phasedistribution calculating means 402 may be reset by an output of thetiming detecting means 10 using the timing of the vertical synchronizingsignal which is currently output, so as to be calculated for each phase.The estimation of the horizontal synchronization phase may be conductedfor each frame, or several times for one frame. As a result, it ispossible to flexibly cope with the updation of the channel and theelectric field state which is changed during one frame, and also toreduce the process.

According to this configuration, the horizontal synchronization phasedistribution is calculated and the horizontal synchronization phase isestimated. Even when radio interference occurs, therefore, a horizontalsynchronization phase which is most accurate can be obtained,disturbance and distortion of an image can be reduced, and an imagehaving a sharp outline can be obtained. Since the input horizontalsynchronizing signal is not restricted by forming a window, it ispossible to flexibly cope with ghost signals in which the pathdifference is large, or with a channel change.

Next, the horizontal synchronization phase input buffer 408 and thevertical synchronization phase input buffer 409 in the configurationshown in FIG. 17 will be described in more detail.

A vertical synchronizing signal input table which will be describedlater corresponds to the vertical synchronization phase input buffer409, and a horizontal synchronizing signal input table to the horizontalsynchronization phase input buffer 408.

First, the horizontal synchronizing signal input table will be describedwith reference to FIG. 18(a).

As described above, when a horizontal synchronizing signal is suppliedfrom synchronizing signal detecting means 3 to horizontalsynchronization phase detecting means 401, a counter 15, a timer, or thelike detects the phase of the signal. The phase is expressed by thevalue of the counter 15 or the timer in which the horizontalsynchronization interval corresponds to one period, and the value of thecounter 15 or the timer in which the vertical synchronization intervalor one frame corresponds to one period. When the horizontalsynchronizing signal is input, the vertical synchronization phase andthe horizontal synchronization phase of the signal are obtained and theninput to a table of a predetermined data number. At the same time, theelectric field information detecting means 7 obtains electric fieldinformation at the timing when the horizontal synchronizing signal isinput, such as the multipath level, the electric field strength, andvariation amounts of these values. The obtained information is input tothe table of the same data number. The reliability of the inputhorizontal synchronizing signal is judged by using the electric fieldinformation. The degree of the reliability is input to the table of thesame data number. These data are recorded in, for example, the line ofdata No. 1 of the horizontal synchronizing signal input table shown inFIG. 18(a) in the sequence starting from the left end of the figure anddirected toward the right end, as vertical synchronization phase 1,horizontal synchronization phase 1, electric field information 1, andreliability 1. In FIG. 18(a), the various kinds of data in the line ofdata No. 1 are data of the horizontal synchronizing signal H_(n) shownin FIG. 15, and the various kinds of data in the line of data No. Jcorrespond to data of the horizontal synchronizing signal H_(j) shown inFIG. 15.

When a histogram is used for representing the horizontal synchronizationdistribution in the estimation of the horizontal synchronization phase,a class in the vicinity of the maximum value of the histogram isobtained, and the horizontal synchronizing signal input table is used inorder to obtain an estimated value.

First, the data of the horizontal synchronization phase and thereliability which are recorded in the horizontal synchronizing signalinput table are checked. Among data included in the class in thevicinity of the maximum value of the horizontal synchronization phase,data of high reliability are extracted from the horizontal synchronizingsignal input table. Next, the average value of the extracted data isobtained to be set as an estimated value of the horizontal phase.Alternatively, the latest one of the extracted data may be set as anestimated value of the horizontal phase, or, in the case where a valuewhich has been estimated in the past is stored, a data which is closestto the past estimated value may be obtained from the extracted data andthen set as an estimated value of the horizontal phase. Alternatively,the distribution of the extracted data may be obtained and a data of themaximum frequency may be set as an estimated value. In the case wheredata included in the vicinity of the class of the maximum value do notexist in the data recorded in the horizontal synchronizing signal inputtable, the past estimated value may be used as it is, a median in thevicinity of the maximum class may be used, or an average of theestimated value and the median in the vicinity of the maximum class maybe used.

According to this configuration, the accuracy of the estimation of thehorizontal synchronization phase can be improved. When a histogram isused for representing the horizontal synchronization distribution, theestimation accuracy can be improved. FIG. 18(b) is a view showing avertical synchronizing signal input table. The table is identical withthe horizontal synchronizing signal input table, and hence itsdescription is omitted.

Next, a horizontal phase frequency table in the horizontalsynchronization phase distribution calculating means 402 of theconfiguration shown in FIG. 17 will be further described.

First, the case where one horizontal phase frequency table is used willbe described with reference to FIG. 19(a).

The phases of horizontal synchronizing signals are classified into an Mnumber (M is an integer) of classes as indicated by phases 1 to M in atable of FIG. 19(a), and the frequency of the input horizontalsynchronization phase is calculated. Specifically, the distribution ofthe count value (see FIG. 16) of the phases of horizontal synchronizingsignals which are input in one frame period always exists between thecount value of 0 and the count value at the timing of the 1 H period,and hence the spread width of the distribution is divided into an Mnumber of classes. Then, the count value of each horizontalsynchronizing signal belonging to each of the divided classes isdetected. The detection frequency, i.e., the number of detections iscalculated for each class. For example, the line indicated as phase 1 inthe table of FIG. 19(a) corresponds to a first class, and the frequencycalculated for the class is recorded as detection frequency 1.

The detection frequency in the frequency table is calculated in thefollowing method. When a vertical synchronizing signal is output, thetable is cleared. The phase frequencies of all horizontal synchronizingsignals which are input until the next vertical synchronizing signal isoutput or during one frame period are obtained for each class. In thisway, the frequency table is obtained, and a class in the vicinity of themaximum class is obtained. With using also the horizontal synchronizingsignal input table (see FIG. 18(a)) which has been described above, thehorizontal synchronization phase estimating means 403 estimates thehorizontal synchronization phase.

The kinds of horizontal phase frequency tables will be described morespecifically with reference to the figures.

As shown in FIGS. 20(a) to 20(d), various kinds of horizontal phasefrequency tables are obtained in accordance with the state of radiointerference.

When the wave strength is sufficiently high and disturbances due tomultipaths and the like less occur, a distribution such as shown in FIG.20(a) is obtained. When the wave level is low, a distribution such asshown in FIG. 20(b) is obtained. When multipaths exist, a distributionsuch as shown in FIG. 20(c) or 20(d) having plural peaks is obtained.

In the case of a distribution such as shown in FIG. 20(a), the peak maybe used as an estimated value of the phase. In the case of adistribution such as shown in FIG. 20(b), similarly, the peak may beused as an estimated value of the phase, and the phase estimation may beaccurately conducted with reference to an average of data of highreliability, or a histogram, a median, and past estimated data of thehorizontal synchronizing signal input table (see FIG. 18(a)).

In the case of a distribution such as shown in FIG. 20(c) or 20(d), anestimated value is obtained on the basis of the peaks of thedistribution, information of the above-mentioned horizontalsynchronizing signal input table, and past output information. If a pastestimated value is at, for example, the maximum peak of the peaks of thedistribution, the value is used as an estimated value. If a pastestimated value is at a peak other than the maximum peak of thedistribution, the decision on whether an estimated value is set to bethe maximum peak or the past peak can be done by using relatively newdata of the horizontal synchronizing signal input table. For example, amethod may be employed in which, if data belonging to the maximum peakexist in a larger number in relatively new data of the horizontalsynchronizing signal input table, the maximum peak of the distributionis used as an estimated value class.

As a result, estimation of the horizontal phase can be realized byobtaining the maximum distribution class, and it can be conducted easilyand correctly. Since plural peaks of a distribution can be obtained anddominant multipaths can be specified from the peaks, a skip and flickerof an image can be reduced. A peak of a distribution can be obtained,and components of multipaths can be obtained from the peak. The delaytime of each component can be obtained. According to this configuration,it is possible to conduct ghost cancellation in a video signal.

The case where two horizontal frequency tables 1 and 2 are used will bedescribed with reference to FIGS. 19(a) and 19(b).

In the case where two horizontal frequency tables 1 and 2 are used, thetables are updated in the following manner.

The electric field information at the timing when a horizontalsynchronizing signal is input is checked. When the electric fieldinformation is sufficient or multipaths are small in number, thehorizontal frequency table 1 is updated. When multipaths are large innumber, the horizontal frequency table 2 is updated. If the operation ofclearing the horizontal synchronization phase frequency tables isinhibited during a period other than the channel switching, thehorizontal frequency table 1 shows a steady-state frequency, and thehorizontal frequency table 2 shows the state where multipaths occur. Inthe case of the horizontal phase estimation, when the frequency table 1have a sufficiently large number of data, or, for example, when thetotal number of data in the vicinity of the maximum class or the totaldata number of each class is equal to or larger than a specified value,the horizontal phase can be estimated by using the frequency table 1.When the total number is equal to or smaller than the specified value,the horizontal phase can be estimated by using the frequency tables 1and 2. In the case where the total number is equal to or smaller thanthe specified value, the estimation is conducted in the followingmanner. Plural peaks are obtained from frequency information relating tomultipaths of the frequency table 2, and the peaks are checked to seewhether they exist in the frequency table 1 or not. If exist, relativelynew data of the horizontal synchronizing signal input table are furtherchecked, and a data of a higher frequency and belonging to each peak isused as an estimated value. If the peaks do not exist in the table, apast output phase is selected as an estimated value.

Also when multipaths are many, the horizontal frequency table 1 may besubjected to the updating operation in a duplicate manner. In this case,the frequency table to be used in estimation is determined in accordancewith the number of data in the vicinity of a peak of the distribution.In the above, the embodiment in which the frequency based on countervalues is calculated to obtain the phase distribution has beendescribed. The invention is not restricted to this. For example, aconfiguration in which the phase distribution is treated as an analogvalue may be employed.

According to this configuration, the horizontal phase estimation in thecase of multipaths can be conducted more accurately with excellentresponsiveness.

In the above, the horizontal phase frequency table has been described indetail. The vertical phase frequency table has similar contents as thoseof the horizontal phase frequency table, and hence its description isomitted.

In the above, the embodiment in which the horizontal synchronizationphase signal and the vertical synchronization phase signal are subjectedto estimation of the phase of each signal has been described. Theinvention is not restricted to this. As shown in FIG. 21, for example,the phase estimation may be conducted only on the horizontalsynchronization phase signal. In this case, the horizontal synchronizingsignal can be stabilized, and hence a video signal which is morestabilized can be obtained. FIG. 21 is a view showing the configurationof another embodiment of the synchronizing signal stabilizer.

In the description of the embodiment, the manner of controlling theoutput of the synchronization phase in the case where thesynchronization phase is largely changed has not been particularlydiscussed. In order to smoothly cope with such a case, a configurationshown in FIG. 22 may be employed. FIG. 22 is a view showing theconfiguration of a television video/audio signal receiver of anotherembodiment in which the configuration of the television video/audiosignal receiver shown in FIG. 17 is further provided with: memory means411 for storing an output signal of the synchronizing signal outputtingmeans 407; and comparing means 410 for comparing the stored outputsignal with the horizontal synchronizing signal phase estimated by thehorizontal synchronization phase estimating means 403, for comparing thestored output signal with the vertical synchronizing signal phaseestimated by the vertical synchronization phase estimating means 406,and for correspondingly outputting results of the comparisons to thehorizontal synchronization phase estimating means 403 and the verticalsynchronization phase estimating means 406. In the embodiment, thehorizontal synchronization phase estimating means 403 and the verticalsynchronization phase estimating means 406 shown in FIG. 22 conduct thephase estimation by utilizing also the comparison results output fromthe comparing means. Specifically, the memory means 411 stores previoussynchronization phases. The comparing means 410 compares thesynchronization phase output from the horizontal synchronization phaseestimating means 403 or the vertical synchronization phase estimatingmeans 406, with the previous synchronization phases stored in the memorymeans 411. When a channel is to be switched over, for example, there isa possibility that the result of the comparison shows a largedifference. Even if the phase is largely changed, the phase is notimmediately output. Specifically, in order to wait for stabilization ofthe variation of the synchronization phase, the comparing means 410follows the change of the phase after an elapse of a fixed time from thetiming when the phase is largely changed. Therefore, the comparing means410 controls the synchronization phase estimating means 403 and 406 soas to output a phase obtained before the timing when the phase islargely changed. According to this configuration, it is possible tooutput a phase which does not follow the erroneous phase variation dueto malfunction or the like and which is further stabilized. Thetelevision video/audio signal receiver shown in FIG. 22 furthercomprises correcting means 412. The correcting means 412 compares theoutput signal stored in the memory means 411 with the estimatedhorizontal synchronization phase signal obtained from the horizontalsynchronization phase estimating means 403, and, in accordance with theresult of the comparison, corrects a change of the estimated horizontalsynchronization phase signal which is caused by disturbance of the clocksignal due to malfunction of the clock signal generating means 14 or thelike. Specifically, the correcting means 412 compares the output phaseof the horizontal synchronization phase estimating means 403 with theprevious phase of the memory means 411. As a result, if it is judgedthat the output phase of the horizontal synchronization phase estimatingmeans 403 tends to be gradually increased or reduced for each frame, forexample, the correcting means 412 judges that such a phase change iscaused by an abnormality of the clock signal, and conducts a correctionfor eliminating the change. Since the correcting means 412 is disposedin this way, it is possible to obtain a video signal which is furtherstabilized.

(Embodiment 4)

FIG. 23 is a view diagrammatically showing the configuration of atelevision video/audio signal receiver which is an embodiment using theluminance signal stabilizer of the invention.

The configuration of the embodiment will be described with reference tothe figure. The components which are fundamentally identical with thosedescribed with reference to FIG. 3 and the like are designated by thesame reference numerals, and their description is omitted. FIG. 23 is aview showing in more detail the video signal stabilizing means 8 of thetelevision video/audio signal receiver of FIG. 3. A luminance signalstabilizer 800 corresponds to the video signal stabilizing means 8.Hereinafter, therefore, the internal configuration of the luminancesignal stabilizer 800 will be mainly described.

As shown in FIG. 23, the luminance signal stabilizer 800 comprises thefollowing means. Luminance reference signal detecting means 801 obtainsa luminance reference signal of a video signal included in the receivedsignal received by the receiving means 2, by using the stabilizedsynchronizing signal of the video signal. Luminance informationcalculating means 804 calculates luminance information from theluminance reference signal and holds the calculated luminanceinformation. Luminance reference signal judging means 802 judgesreliability of the luminance reference signal by using the luminanceinformation held in the luminance information calculating means 804.Pedestal clamp interpolation controlling means 803 conducts aninterpolation generation control of the luminance reference signal onthe basis of a result of the judgement. On the basis of the result ofthe judgement, luminance reference signal interpolating means 805outputs the luminance reference signal with interpolating the luminancereference signal in accordance with interpolation information obtainedfrom Pedestal clamp interpolation controlling means 803, or outputs theluminance reference signal without conducting the interpolation.Electric field information detecting means 7 detects electric fieldinformation from a signal obtained from the receiving means 2. When theluminance information is to be calculated, the luminance informationcalculating means 804 utilizes the electric field information, and, whenthe judgement is to be conducted, the luminance reference signal judgingmeans 802 utilizes also the electric field information. The luminancereference signal interpolation controlling means in the inventioncorresponds to the pedestal clamp interpolation controlling means 803.

The operation of the thus configured embodiment will be described withreference to FIGS. 23 and 24.

Referring to FIG. 23, the luminance reference signal of the video signalobtained in the receiving means 2 is detected by the luminance referencesignal detecting means 801. In this case the position where theluminance reference signal exists can be correctly obtained by using thestabilized synchronizing signal obtained from the synchronizing signalstabilizing means 4.

The luminance reference signal judging means 802 judges the stabilityand reliability of the luminance reference signal supplied from theluminance reference signal detecting means 801. The luminance referencesignal is a signal which is an object of the interpolating process. Inthe judgment, the luminance information obtained from the luminanceinformation calculating means 804, and the electric field informationobtained from the electric field information detecting means 7. Theluminance information corresponds to an interpolation value which willbe described later.

As the method of calculating the luminance information in the luminanceinformation calculating means 804, a method in which average luminanceinformation is obtained for each frame of an image may be employed. Theaverage luminance information for each frame may be obtained while, byusing the electrical field information, excluding multipaths and a statein which the electric field is weak or that in which the electric fieldis largely varied. As a luminance average of a frame, an average withina range of several frames may be calculated. Alternatively, theluminance average may be obtained for each line (for each horizontalsynchronizing signal), or for plural lines.

In the embodiment, as shown in FIG. 24, the luminance informationcalculating means 804 calculates luminance information by using theluminance reference signal obtained from a signal 501 b which existsbetween a video signal 501 a received immediately before a horizontalsynchronizing signal 503 and the horizontal synchronizing signal 503,and holds the information. The luminance reference signal interpolatingmeans 805 conducts the interpolation by using the luminance informationon a luminance reference signal 501 c in a period from a timing which isimmediately after the horizontal synchronizing signal 503 to a timingwhich is immediately before a video signal 501 d sent subsequent to thehorizontal synchronizing signal 503. In other words, in accordance withthe luminance information, the zone in which interpolation is to beconducted is a zone from the end of a horizontal synchronizing signal tothe beginning of the next video signal. As shown in the figure, theluminance reference signal 501 c suffers two disturbances, i.e., apedestal level disturbance and a color burst disturbance. Aninterpolated video signal 502 shown in the figure is a result of anoperation in which also a stabilizing process of a color referencesignal conducted in another embodiment described later is applied. Inthe case where only a stabilizing process of the luminance referencesignal is conducted, a signal 502 a shown in the figure which hasundergone pedestal level interpolation is added to a color burst signal.In the case where only a stabilizing process of the color referencesignal is conducted, a signal 502 b shown in the figure which hasundergone color burst interpolation is added to the DC value of thecolor burst signal as described later.

Specifically, the pedestal clamp interpolation controlling means 803sends a judgment result output from the luminance reference signaljudging means 802 and on whether interpolation of a luminance signal isto be conducted or not, and the luminance information which is to beused as the interpolation value and which is output from the luminanceinformation calculating means, to the luminance reference signalinterpolating means 805. If a judgment result indicating thatinterpolation of a luminance signal is to be conducted is obtained, theluminance reference signal interpolating means 805 conductsinterpolation of the luminance reference signal. By contrast, if ajudgment result indicating that interpolation of a luminance signal isnot to be conducted is obtained, the luminance reference signalinterpolating means 805 uses the luminance reference signal (in FIG. 24,a signal corresponding to the luminance reference signal 501 c) sentfrom the luminance reference signal detecting means 801 to the luminancereference signal judging means 802, as it is, and does not conduct theinterpolating process.

When the luminance reference signal interpolating means 805 is toconduct the process of interpolation, the process may be realized byinterpolating and replacing the waveform included in the luminancereference signal in the video signal level, or by merely adding the DCvalue during a period including the luminance reference signal. Whenvalues of DC components are subjected to addition or the like in thisway, also the color burst signal which is a color signal is improved.When the luminance reference signal is obtained as a digital signal, theluminance reference signal may be replaced with an interpolated value orthe interpolation level may be added or subtracted. In an actual videosignal process, the luminance reference signal has a pedestal level andcan be realized by interpolation of the pedestal clamp level. Since thestabilized horizontal synchronizing signal is used, the sample timing ofthe pedestal clamp level in the luminance reference signal detectingmeans can be correctly obtained.

Since the luminance reference signal is stabilized in this way, flickerof a screen can be prevented from occurring, thereby producing an imagewhich is easy to watch. The use of electric field information enablesthe disturbance zone of the video reference signal to be correctlydetected, and also a reference signal which does not suffer adisturbance to be identified. Therefore, a correct interpolated valuecan be obtained. Furthermore, it is possible to correctly identify areference signal which must be interpolated. As a result, flicker of theluminance signal due to wave interference can be improved veryaccurately, and hence an image which is easy to watch can be obtained.Moreover, the embodiment is particularly effective in the case ofmultipaths due to a delayed signal or a disturbance of the videoreference signal caused by post ghost. Luminance information iscalculated from a signal immediately before a synchronizing signal andthe information is estimated as correct luminance reference information.Even when a disturbance occurs after the synchronizing signal,therefore, a correct video reference signal can be obtained and theinterpolation level can be correctly estimated, with the result that theimage quality can be improved.

In the above, the embodiment in which the luminance informationcalculating means calculates luminance information by using theluminance reference signal obtained from a signal existing between avideo signal received immediately before a synchronizing signal and thesynchronizing signal has been described. The invention is not restrictedto this. For example, a configuration may be employed in which theluminance information calculating means calculates the luminanceinformation by using a luminance reference signal obtained between avideo signal received immediately before a synchronizing signal and thesynchronizing signal, and also the luminance reference signal obtainedin a period from a timing which is immediately after the synchronizingsignal to a timing which is immediately before a video signal sentsubsequent to the synchronizing signal. Also in this case, the sameeffect as described above, i.e., the effect that an image which is easyto watch can be obtained is attained.

In the above, the embodiment in which a stabilized synchronizing signalis used has been described. The invention is not restricted to this. Forexample, a synchronizing signal is not required to have undergone astabilizing process.

In the above, the embodiment in which electric field information is usedhas been described. The invention is not restricted to this. Forexample, a configuration in which electric field information is not usedmay be employed.

In the above, the embodiment in which the luminance reference signal isstabilized has been described. The invention is not restricted to this.As shown in FIG. 25, for example, a color reference signal may bestabilized in a configuration which is fundamentally identical with thatdescribed above. FIG. 25 shows a color signal stabilizer 820 which isanother embodiment, and is a view showing in more detail the videosignal stabilizing means 8 of the television video/audio signal receiverof FIG. 3. The color signal stabilizer 820 corresponds to the videosignal stabilizing means 8. As shown in FIG. 25, color reference signaldetecting means 821 obtains a color reference signal of a video signalincluded in a received signal received in the receiving means 2, byusing the stabilized synchronizing signal of the video signal. Colorinformation calculating means 824 calculates color information from thecolor reference signal and holds the calculated color information. Colorreference signal judging means 822 judges reliability of the colorreference signal by using the color information held in the colorinformation calculating means 824. Color reference signal interpolationcontrolling means 823 conducts an interpolation generation control ofthe color reference signal on the basis of a result of the judgement. Onthe basis of the result of the judgement, color reference signalinterpolating means 825 outputs the color reference signal withinterpolating the color reference signal in accordance withinterpolation information obtained from the color reference signalinterpolation controlling means 823, or outputs the color referencesignal without conducting the interpolation. Electric field informationdetecting means 7 detects electric field information from a signalobtained from the receiving means 2. When the color information is to becalculated, the color information calculating means 824 utilizes theelectric field information, and, when the judgement is to be conducted,the color reference signal judging means 822 utilizes also the electricfield information. Also in the embodiment, the same effect as describedabove, i.e., the effect that an image which is easy to watch can beobtained is attained.

In the above, the embodiments in which the image stabilizing meansstabilizes one of the luminance reference signal and the color referencesignal have been described. The invention is not restricted to them. Asshown in FIG. 26, for example, a configuration in which both theluminance reference signal and the color reference signal are stabilizedmay be employed. In this case, as shown in FIG. 26, video signalsynthesizing means 830 synthesizes the video signal, the luminancereference signal output from the luminance reference signalinterpolating means 805 (see FIG. 23), and the color reference signaloutput from the color reference signal interpolating means 825 (see FIG.25) with each other, and outputs the synthesized video signal. Accordingto this configuration, an effect that which is further easy to watch canbe attained. FIG. 26 shows a video signal stabilizer which is anotherembodiment, and is a view showing in more detail the video signalstabilizing means 8 of the television video/audio signal receiver ofFIG. 3.

In the description of the embodiment, the manner of controlling thevideo signal output from the video signal synthesizing means has notbeen particularly discussed. As shown in FIG. 27, for example, theconfiguration of FIG. 26 may be modified so as to further comprise videoinformation processing means 831, a video frame memory 832, and videooutput controlling means 833. Specifically, as shown in FIG. 27, thevideo frame memory 832 stores the video signal, and the videoinformation processing means 831 processes the synthesized video signalobtained from the video signal synthesizing means 830, and the videosignal stored in the video frame memory, on the basis of a synchronizingsignal which has undergone a predetermined stabilizing process and theelectric field information, and outputs video data to the video framememory. The video output controlling means 833 selects one of the videosignal obtained from the video signal synthesizing means 830, and thevideo signal obtained from the video frame memory 832, on the basis ofthe stabilized synchronizing signal output from the synchronizing signalstabilizing means 4, the electric field information from the electricfield information detecting means 7, and a control signal from the videoinformation processing means 831, and outputs the selected video signal.In this case, when multipaths obtained from the electric fieldinformation exceed a predetermined reference, the video signal obtainedfrom the video frame memory 832 may be selected, whereby a video signalwhich is further stabilized can be output. In this case, preferably, theselected video signal is a video signal immediately before a videosignal in which multipaths exceed the predetermined reference.

In the above, the embodiment in which, in order to stabilize the videosignal, the luminance reference signal or the color reference signal isstabilized has been described. However, the manner of stabilizing thevideo signal is not restricted. Therefore, the stabilizer may berealized by, for example, a configuration comprising: electric fieldinformation detecting means for detecting electric field informationfrom an input received signal; a video frame memory which stores a videosignal of the received signal; video signal stabilizing means forconducting a stabilizing process on the video signal; and video outputcontrolling means for, by using the electric field information,selecting one of the video signal obtained from the video signalstabilizing means, and the video signal obtained from the video framememory, and for outputting the selected video signal. According to thisconfiguration, a video signal can be selected by using the electricfield information, and hence a video signal which is further stabilizedcan be output.

The embodiments described above may be realized by hardware usingelectronic circuits and the like, or a software using programs.

As apparent from the above description, the invention has an advantagethat an incoming video signal can be further stabilized as compared withthe prior art, or that noises of an incoming audio signal can be furtherreduced as compared with the prior art.

Hereinafter, embodiments of the invention will be described withreference to the drawings.

(Embodiment 5)

FIG. 28 is a view showing the configuration of a television signalreceiver which is an embodiment of the invention.

The configuration of the embodiment will be described with reference tothe figure. Receiving means 301 receives a television signal. Pulsedetecting means 302 detects an equalizing pulse of a video signalobtained from the receiving means 301, and phase detecting means 303detects the phase of the pulse obtained from the pulse detecting means302. Ghost detecting means 304 detects an amount of ghosts included inthe video signal obtained from the receiving means 301, by using a ghostdetection reference signal (GCR) included in the video signal. Videosignal stabilizing means 305 stabilizes an image on the basis of theghost amount obtained in the ghost detecting means and controlinformation obtained in the equalized phase detecting means 303, anddisplaying means 306 displays an image on the basis of a stabilizedvideo signal obtained from the video signal stabilizing means 305.

The operation of the thus configured embodiment will be described withreference to FIG. 28.

The receiving means 301 detects and generates a video signal from thetelevision signal.

The pulse detecting means 302 detects pulses included in the videosignal and transmits the pulses to the phase detecting means 303.

The phase detecting means 303 prepares a distribution of phases in whichpulses are generated in the obtained pulse interval, and detects anormal pulse phase and an abnormal pulse phase. The manner of theoperation is shown in FIG. 29.

As an example of the preparation of the phase distribution, a case inwhich the pulse detecting means 302 detects an equalizing pulse in avertical blanking interval and the phase detecting means 303 detects thephase of the equalizing pulse will be considered. In this case, thefalling or rising edge of the equalizing pulse interval detected by thepulse detecting means 302 may be used in the phase distribution. In FIG.29, the abscissa indicates one half of the phase of the period of thehorizontal synchronization, and the ordinate indicates the occurrencefrequency. In the figure, (a) shows the equalized phase distribution inthe case where the video signal which does not suffer a disturbance, and(b) shows a state in which the video signal suffers a disturbance due tomultipaths or the like. In (a) of the figure, a peak appears at aposition which is substantially equivalent to the phase of a horizontalsynchronizing signal or which is offset from the phase by a fixedamount. By contrast, in the case of a video signal which suffers adisturbance due to multipaths, plural peaks may appear in addition tothe peak of (a). The phase differences of the peak positions indicatethe delay times of ghosts, and the frequency difference of the peakvalues indicates the disturbance amount or the ghost amount. As thefrequency difference of the peak values is smaller, the disturbanceamount is judged to be larger.

On the other hand, the ghost detecting means 304 detects ghostcomponents included in the video signal. In the detection of ghosts, atechnique such as that in which the ghost cancel signal (GCR) includedin the video signal is used, or that in which autocorrelation of thevideo signal is obtained may be employed.

The video signal stabilizing means 305 conducts a stabilizing process onthe video signal by using the phase and amount of the image disturbanceobtained from the phase detecting means 303, and a transfer function ofthe ghost amount or ghost components obtained from the ghost detectingmeans 304. The object of the stabilizing process on the video signal isa ghost, and the phenomena include multiple images and image skip. As animage stabilizing processing method, a method in which video signalsprovided with a phase difference are added to each other, or that inwhich a multiplication of the reciprocal of a transfer function ofghosts is performed may be employed. Particularly, ghosts can beeffectively eliminated by, in the case where the ghost detecting means304 can obtain a transfer function of ghosts, using the reciprocal ofthe transfer function, and, in the case where the delay time and thedelay amount can be obtained from the phase detecting means 303, addingvideo signals having a phase difference with each other.

In the displaying means 306, the video signal obtained from the videosignal stabilizing means 305 is displayed on a display device such as aCRT, a liquid crystal display device, or a plasma tube.

In this way, a stabilized video signal can be obtained.

In the above, the receiver comprising the ghost detecting means has beendescribed. The invention is not restricted to this. As shown in FIG. 30,a configuration which is not provided with ghost detecting means may beemployed. FIG. 30 shows a television signal receiver as another examplewhich is not provided with the ghost detecting means 304 of thetelevision signal receiver shown in FIG. 28. As shown in the figure, thetelevision signal receiver comprises: receiving means 301 for receivinga television signal; pulse detecting means 302 for detecting a pulse ofa video signal obtained from the receiving means; phase detecting means303 for detecting the phase of the pulse; video signal stabilizing means305 for conducting image-stabilization on the video signal obtained inthe receiving means 301, on the basis of control information obtainedfrom the phase detecting means 303; and displaying means 306 fordisplaying a video signal obtained from the video signal stabilizingmeans 305. In this case, the phase detecting means can detect adisturbance of the video signal, and hence it is possible to attaineffects which are substantially equivalent to those of the embodimentdescribed above.

In the above, the receivers respectively with and without the ghostdetecting means have been described. The invention is not restricted tothis. As shown in FIG. 31, a configuration which is provided with theghost detecting means 304 and controlled by the phase detecting means303 may be employed. FIG. 31 shows a television signal receiver asanother example in which the ghost detecting means 304 of the televisionsignal receiver shown in FIG. 28 is controlled by the phase detectingmeans 303. As shown in the figure, the television signal receivercomprises: receiving means 301 for receiving a television signal; pulsedetecting means 302 for detecting a pulse of a video signal obtainedfrom the receiving means 301; phase detecting means 303 for detectingthe phase of the pulse; ghost detecting means 304 for detecting a ghostof the video signal, on the basis of a control signal obtained from thephase detecting means 303; video signal stabilizing means 305 forconducting image-stabilization on the video signal obtained from thereceiving means, on the basis of control information obtained from theghost detecting means 304; and displaying means 306 for displaying avideo signal output from the video signal stabilizing means 305. Thephase detecting means 303 previously gives the delay times and delayamounts of ghosts to the ghost detecting means 304. Therefore, the ghostdetecting means 304 can rapidly calculate the transfer function ofghosts by using the GCR, etc. In this case, effects which aresubstantially equivalent to those of the embodiment described above canbe attained rapidly and correctly.

(Embodiment 6)

FIG. 32 is a view diagrammatically showing the method of transmitting atelevision signal of the invention in which a control signal is insertedinto a video signal.

The embodiment will be described with reference to the figure whichshows the contents of a television signal. The reference numeral 310designates a vertical blanking interval, 311 designates a video signalinterval, 312 designates an anterior equalizing pulse interval, 313designates a vertical synchronizing signal interval, 314 designates aposterior equalizing pulse interval, 315 designates a reserve videosignal interval, and 316 designates a video signal interval which isfollowed by the video signal interval after an elapse of a predeterminedtime and repeatedly appears. In the figure, (a) shows an example of acontrol signal which is inserted into the anterior equalizing pulseinterval 312, (b) shows an example of a control signal which is insertedinto the vertical synchronizing signal interval 313, and (c) shows anexample of a control signal which is inserted into the posteriorequalizing pulse interval 314. In the reserve video signal interval 315,actually, no display is conducted. Signals such as character signals,the ghost cancel reference signal, and a color phase reference exist inthe interval.

The method of transmitting a television signal of the invention which isconfigured as described above will be described. The figure shows themanners of inserting control signals at positions of a positive level inthe anterior equalizing pulse interval 312, the vertical synchronizingsignal interval 313, and the posterior equalizing pulse interval 314 inthe vertical blanking interval. In the figure, (a), (b), and (c) areenlarged views of one pulse interval of the anterior equalizing pulseinterval 312, the vertical synchronizing signal interval 313, and theposterior equalizing pulse interval 314, respectively. The one intervalis equal to one half of the period of the horizontal synchronizingsignal. In (a), a signal such as sin(x)/x of a positive level and havinga steep edge is inserted at a position of the positive interval. Asimilar signal is inserted into each of (b) and (c). When the televisionsignal shown in the figure is received, in the case where there is noreception abnormality such as multipaths, control signals are obtainedat the same positions as those shown in the figure. In the case wherethere is reception abnormality, a pulse is generated also at a positionother than the positions at which the pulses are inserted. When positivepulses of the received signal obtained in the blanking interval 310 arechecked, therefore, it is possible to know the reception abnormalitystate. If the signal of the maximum positive pulse level among theobtained signals is a correct control signal, signals of a positivelevel other than the signal can be checked to know the phase differenceand the level difference. The transfer function of the receptionabnormality can be known by obtaining the transfer function of themaximum level signal or a control signal which is estimated to becorrect, and signals other than the signal.

As described above, when the method of transmitting a television signalof the invention is used, abnormality of the transmission system can beobtained by using a transfer function, or a delay time and a delayamount. Therefore, abnormality of an image, for example, ghosts such asmultiple images and image skip can be improved.

In the above, the embodiment in which a control signal is inserted intoall of the anterior equalizing pulse interval 312, the verticalsynchronizing signal interval 313, and the posterior equalizing pulseinterval 314 has been described. Alternatively, a configuration in whicha control signal is inserted into the anterior equalizing pulse interval312 and the posterior equalizing pulse interval 314 may be employed. Asingle or plural control signals may be inserted into each zone. Also inthese configurations, it is possible to detect similar receptionabnormality.

In the case where plural control signals are inserted, when the signalsare continuously inserted, the ghost detection ability is restricted toone half phase of the horizontal period because the periods of theequalizing pulse and the vertical synchronizing pulse are one half ofthe horizontal synchronization. However, the ghost detection ability canbe improved to the whole phase of the horizontal period by inserting acontrol signal every other pulse. Furthermore, the detection ability canbe widened by, for example, inserting a control signal on alternatepulses or every two or three pulses. When a pattern in which a controlsignal is continuously inserted is combined with that in which a controlsignal is inserted on alternate pulses, a difference can be producedbetween the detection ability for a disturbed wave of one half of thehorizontal period or less, and that for other waves, with the resultthat the disturbed wave detection can be effectively conducted.

In the embodiment, a steep pulse is inserted as a control signal.Alternatively, a control signal such as those shown in FIGS. 6 and 7 maybe inserted. The television signal is configured in the same manner asthat of FIG. 32, and hence its description is omitted.

In FIG. 33, (a), (b), and (c) show waveforms of inserted controlsignals. The control signals have rectangular waveforms. FIG. 34 showsthe case where a step function is inserted as a control signal. Also inthis case, it is possible to detect similar reception abnormality asthat in the embodiment described above.

When the control signals are to be inserted in (a), (b), and (c) ofFIGS. 5, 6, and 7, the phase from the falling edge of the correspondingpulse of one period of each of the anterior equalizing pulse interval312, the posterior equalizing pulse interval 314, and the verticalsynchronizing signal interval 313 may be controlled so that the controlsignals are inserted at the same phase. This enables the method to exerta further correct ability of detecting reception abnormality.

In the embodiment described above, the control signal is inserted intothe anterior equalizing pulse interval 312, he vertical synchronizingsignal interval 313, and the posterior equalizing pulse interval 314.The control signal may be inserted also into the reserve video signalinterval 315. In this case, the control signals are increased in numberand hence reception abnormality can be detected more correctly.

Also in the case of a television signal in which the GCR such as theghost cancel signal is previously inserted into the reserve video signalinterval, the control signal according to the invention can be furtherinserted. In this configuration, the present invention causes the numberof control signals to be further increased. Therefore, the ghostdetection can be conducted more rapidly.

(Embodiment 7)

FIG. 35 is a view showing the configuration of a television signalreceiver which is an embodiment of the invention.

The configuration of the embodiment will be described with reference tothe figure. The components which are fundamentally identical with thoseof the embodiment described with reference to FIG. 28 and the like aredesignated by the same reference numerals, and their description isomitted. As shown in FIG. 35, as compared with the embodiment of FIG.28, the ghost detecting means 304 of FIG. 28 is replaced with controlsignal detecting means 307.

Hereinafter, the control signal detecting means 307 of the embodimentwill be described. A control signal such as that used in the method oftransmitting a television signal of the invention is inserted into atelevision signal. The control signal detecting means 307 detects thecontrol signal from the television signal. For example, the case where atelevision signal shown in FIG. 32 is received will be considered.First, when a video signal is not disturbed, a reception waveformsimilar to that of FIG. 32(a) can be obtained. When a video signal isdisturbed, a single pulse such as shown in FIG. 32(a) does not appear,but instead plural pulses appear at various levels. The control signaldetecting means 307 in the embodiment detects the disturbance amountfrom the control signal in such a disturbed state. The means has afunction of obtaining the disturbance amount, such as the delay time ofa ghost, the ghost amount, or a transfer function of a ghost and adisturbed signal. Ghosts are detected in the equalizing pulse intervalor the vertical synchronizing signal interval in the vertical blankinginterval.

On the basis of the disturbed state or the ghost state obtained by thedisturbed signal detecting function of the control signal detectingmeans 307 and the disturbed state detecting function due to pulsedetecting means 302 and phase detecting means 303, video signalstabilizing means 305 stabilizes the video signal. As a result, imagestabilization which is superior to that of the embodiment describedabove can be conducted.

In the embodiment, disturbance information obtained in the phasedetecting means 303 is transmitted only to the video signal stabilizingmeans 305. Alternatively, the disturbance information may be transmittedalso to the control signal detecting means 307, thereby enabling thecontrol signal detecting means 307 to obtain a transfer function ofdisturbance more rapidly. In the alternative, the responsiveness ofeliminating a disturbance is enhanced, so that the receiver operatesmore effectively in the use of mobile reception.

In the above, the embodiment of the television signal receiver whichcomprises the pulse detecting means 302 and the phase detecting means303 has been described. The invention is not restricted to this. Asshown in FIG. 36, for example, a configuration which, in place of thesemeans, uses synchronizing signal detecting means 81 and synchronizationphase detecting means 82 may be employed. As shown in the figure, thereceiver comprises: receiving means 301; the synchronizing signaldetecting means 81 for detecting a synchronizing signal of a signalobtained from the receiving means 301; the synchronization phasedetecting means 82 for detecting the phase of the synchronizing signalobtained from the synchronizing signal detecting means 81; controlsignal detecting means 307 for detecting a control signal from the videosignal obtained in the receiving means 301; video signal stabilizingmeans 305 for stabilizing the video signal on the basis of controlinformation obtained from the control signal detecting means 307. anddisturbance information obtained from the synchronization phasedetecting means 82; and displaying means for displaying the signal.

The operations of the synchronizing signal detecting means 81 and thesynchronization phase detecting means 82 will be described. Thesynchronizing signal detecting means 81 detects synchronizing signalsfrom the video signal, and the synchronization phase detecting means 82prepares the distribution of the obtained synchronizing signals. Thisfunctions in the same manner as the phase detecting means 303 of FIG.28, and hence a synchronization phase distribution similar to that shownin FIG. 29 can be obtained. In this case, however, the period isobtained with using one horizontal period as a reference. In the samemanner as the phase detecting means 303, also the synchronization phasedetecting means 82 can obtain the disturbed state of the video signal,and the delay time and delay amount of a ghost.

As described above, also the embodiment in which the pulse detectingmeans 302 and the phase detecting means 303 are respectively replacedwith the synchronizing signal detecting means 81 and the synchronizationphase detecting means 82 can attain effects which are equivalent tothose of the embodiment described above.

In the embodiment, disturbance information obtained in the phasedetecting means 82 is transmitted only to the video signal stabilizingmeans 305. Alternatively, the disturbance information may be transmittedalso to the control signal detecting means 307, thereby enabling thecontrol signal detecting means 307 to operate rapidly and correctly.

The embodiment of FIG. 36 may be modified so as to further comprisesynchronizing signal stabilizing means 83. FIG. 37 shows a televisionsignal receiver to which the synchronizing signal stabilizing means 83is added. As shown in the figure, the receiver comprises: receivingmeans 301; synchronizing signal detecting means 81 for detecting asynchronizing signal of a signal obtained from the receiving means 301;synchronization phase detecting means 82 for detecting a phase of thesynchronizing signal obtained from the synchronizing signal detectingmeans 81; synchronizing signal stabilizing means 83 for estimating acorrect phase from the phase of the synchronizing signal obtained fromthe synchronization phase detecting means; control signal detectingmeans 307 for detecting a control signal from a video signal obtained inthe receiving means 301; video signal stabilizing means 305 forstabilizing the video signal on the basis of a stabilized synchronizingsignal obtained in the synchronizing signal stabilizing means 83; anddisplaying means for displaying the signal. The synchronizing signalstabilizing means 83 estimates a correct horizontal synchronizationphase or a vertical synchronization phase from the phase distributionsuch as that shown in FIG. 29, and generates the stabilizedsynchronizing signal. Therefore, the television signal receiver of theembodiment can attain an effect that distortion or a flow of a videosignal due to a lack or abnormality of synchronization can be reduced,in addition to the effects of the television signal receiver describedabove.

In the above, the embodiment which uses the control signal detectingmeans 307 has been described. As shown in FIG. 38, the embodiment may bemodified so as to use ghost detecting means 304.

FIG. 38 is a view showing the configuration of a television signalreceiver as another example which uses the ghost detecting means 304 inplace of the control signal detecting means 307 of the television signalreceiver of FIG. 37. As shown in the figure, the television signalreceiver comprises: receiving means 301; synchronizing signal detectingmeans 81 for detecting a synchronizing signal of a signal obtained fromthe receiving means 301; synchronization phase detecting means 82 fordetecting the phase of the synchronizing signal obtained from thesynchronizing signal detecting means 81; synchronizing signalstabilizing means 83 for estimating a correct phase from the phase ofthe synchronizing signal obtained from the synchronization phasedetecting means 82; ghost detecting means 304 for detecting a ghostcancel signal from a video signal obtained from the receiving means 301,on the basis of control information from the synchronization phasedetecting means 82; video signal stabilizing means 305 for stabilizingthe video signal on the basis of disturbance information of a receivedsignal obtained from ghost detecting means 304 and a stabilizedsynchronizing signal obtained in the synchronizing signal stabilizingmeans 83; and displaying means for displaying the signal. In this case,the synchronization phase detecting means 82 previously gives a ghostsignal to the ghost detecting means 304, and hence it is possible toattain an effect that the process is conducted rapidly and correctly, inaddition to the effects of the embodiment described above. Even when thecontrol information obtained in the synchronization phase detectingmeans 82 is independently transmitted to the video signal stabilizingmeans 305, it is possible to attain effects which are substantiallyequivalent to those of the embodiment described above.

In the above, the embodiment which comprises the ghost detecting means304 in place of the control signal detecting means 307 has beendescribed. The invention is not restricted to this. A configuration inwhich both the control signal detecting means 307 and the ghostdetecting means 304 are disposed may be employed. FIG. 39 shows atelevision signal receiver in which control signal detecting means isadded to the configuration of the television signal receiver of FIG. 38.As shown in the figure, the receiver comprises: receiving means 301;synchronizing signal detecting means 81 for detecting a synchronizingsignal of a signal obtained from the receiving means 301;synchronization phase detecting means 82 for detecting the phase of thesynchronizing signal obtained from the synchronizing signal detectingmeans 81; synchronizing signal stabilizing means 83 for estimating acorrect phase from the phase of the synchronizing signal obtained fromthe synchronization phase detecting means; ghost detecting means 304 fordetecting a ghost cancel signal from a video signal obtained from thereceiving means 301, on the basis of control information from thesynchronization phase detecting means 82; control signal detecting means307 for detecting a control signal from a video signal obtained in thereceiving means 301; video signal stabilizing means 305 for stabilizingthe video signal on the basis of disturbance information of a receivedsignal obtained from the control signal detecting means 307 and astabilized synchronizing signal obtained in the synchronizing signalstabilizing means 83; and displaying means for displaying the signal. Inthis case, it is possible to attain an effect that the process isconducted rapidly and correctly, as compared with the embodimentdescribed above.

Hereinafter, relationships between the ghost detecting means 304 and thesynchronization phase detecting means 82 will be described.

In the ghost detecting means 304, the accuracy of the result of theghost detection using the GCR can be improved on the basis of thedetection result of the synchronization phase detecting means 82, andthe detection speed can be enhanced by using a signal in thesynchronization phase detecting means 82.

Next, the operation will be described. In the synchronization phasedetecting means 82, as shown in FIGS. 20(A) to 20(D), the phase of thesynchronizing signal is detected on the basis of the synchronizationphase distribution (FIG. 20(A)), and, when ghosts occur, a distributionsuch as that shown in FIG. 20(C) or 20(D) is obtained. As a result, itis possible to detect also the phase of a ghost signal. The phase of thesynchronizing signal and the ghost phase obtained in the synchronizationphase detecting means 82 are compared with the ghost phase obtained inthe ghost detecting means 304. If the ghost phases are substantiallyidentical with each other, the ghost detecting means 304 transmits theresult of the ghost detection to the video signal stabilizing means 305.If the ghost phases of the ghost detecting means 304 and thesynchronization phase detecting means 82 are not close to each other,there is a possibility that erroneous detection has occurred, and henceit is judged that a ghost does not occur. (This is effective in the casewhere the time constant of the ghost detecting means is set to be smallin order to cope with varying ghosts. There is a high possibility thatthe result of the ghost detection obtained from the ghost detectingmeans 304 by using the GCR contain many errors. Therefore, thesynchronization phase detecting means 82 is used as data forverification. This can improve the accuracy and the detection speed.)When the detection speed of the ghost detecting means 304 is set so asto have a sufficiently large time constant, the result of the detectionof the ghost detecting means 304 using the GCR may be output as it is,irrespective of the result of the synchronization phase detecting means82 (under conditions which are set so that no ghost occurs, such as thecase where the antenna is fixed). When one of the detection of the ghostdetecting means 304 using the GCR, and the synchronization phasedetecting means 82 indicates that several ghosts of the same degrees arecontinuously detected, it may be judged that ghosts occur. When ghostsof the same degrees are alternatingly detected, it may be judged thatghosts occur. In these cases, ghost detection can be rapidly conducted.

As apparent from the above description, the invention can provide atelevision signal for facilitating detection of a disturbance of areceived video signal, whereby the received video signal can be furtherstabilized as compared with the prior art, and also an image in which,even when the disturbance state is changed in mobile reception, highfollowability is obtained and which is therefore easy to watch.

What is claimed is:
 1. A television receiver comprising: receiving meansfor receiving a television signal; synchronizing signal detecting meansfor detecting a synchronizing signal of a video signal obtained fromsaid receiving means; electric field information detecting means fordetecting electric field information from a signal obtained from saidreceiving means; synchronizing signal stabilizing means for stabilizingthe detected synchronizing signal on the basis of the electric fieldinformation; display controlling means for controlling a display of thevideo signal by using the stabilized synchronizing signal; anddisplaying means for displaying a signal output from said displaycontrolling means.
 2. A television receiver according to claim 1,wherein objects which are to stabilized by said video signal stabilizingmeans include a luminance signal, a color signal, ghosts, and an imageskip.
 3. A television receiver comprising: receiving means for receivinga television signal; synchronizing signal detecting means for detectinga synchronizing signal of a video signal obtained from said receivingmeans; synchronizing signal stabilizing means for stabilizing thedetected synchronizing signal; video signal stabilizing means forstabilizing the video signal obtained from said receiving means, byusing the stabilized synchronizing signal, and for outputting thestabilized video signal; display controlling means for controlling adisplay of the stabilized video signal by using the stabilizedsynchronizing signal; and displaying means for displaying a signaloutput from said display controlling means; wherein said receiverfurther comprises electric field information detecting means fordetecting electric field information from a signal obtained from saidreceiving means, said synchronizing signal stabilizing means stabilizesthe synchronizing signal on the basis of the electric field informationobtained from said electric field information detecting means, and/orsaid video signals stabilizing means stabilizes the video signal byusing also the electric field information obtained from said electricfield information detecting means.
 4. A television receiver according toclaim 3, wherein said receiver further comprises: noise predicting meansfor predicting noises of an audio signal obtained from said receivingmeans, on the basis of the obtained electric field information; noisecanceling means for reducing noises of the audio signal on the basis ofthe predicted noises obtained from said noise predicting means and theobtained electric field information; and audio signal reproducing meansfor reproducing an audio signal output from said noise canceling means.